Fringed surface structures obtainable in a compression molding process

ABSTRACT

Disclosed are mono-layer or multi-layer films, sheets, or coatings wherein at least on layer comprises a fringed surface microstructure (1), a process for making these items and uses thereof. Further disclosed are articles of manufacture comprising such film, sheet, or coating.

This application is a 35 U.S.C. §371 nationalized application ofPCT/US00/19320, filed Jul. 17, 2000, which claims priority to U.S.provisional application Ser. No. 60/144,306 filed Jul. 16, 1999 and toU.S. provisional application Ser. No. 60/153,793, filed Sep. 14, 1999,incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to a surface having a fringed microstructure andto a mono-layer or multi-layer film, sheet, or coating characterized inthat it comprises at least one layer which has or comprises a fringedsurface microstructure. The invention also provides a process and adevice to make such film, sheet, or coating, uses thereof, as well asarticles of manufacture made therefrom.

BACKGROUND OF THE INVENTION

Plastic articles and items with a pleasant haptic appearance, such as atextile-like touch, and good optics are desirable for numerousapplications, including hygienic products or garments. To improveaesthetics, for example of a plastic film, various techniques of surfacemodification resulting in various surface structures have been employed.Known surface-structured films include apertured films and non-aperturedfilms.

Surface-structured apertured films include films wherein the aperture isin the plane of the film, irrespective of any surface structure orpattern, and films which are apertured through the surface feature, e.g.the protruberance.

For example, U.S. Pat. No. 4,629,643 provides a micro-aperturedpolymeric web exhibiting a pattern of discrete volcano-like aberrations,the end of which includes at least one micro-aperture at its point ofmaximum amplitude. The films are produced by impinging a jet of highpressure liquid on the exposed surface of a web of flat polymeric filmwhile said film is supported on a fine mesh woven wire support member.The high pressure fluid jet causes micro-aperturing of those portions ofthe web which coincide with the interstices between the intersectingwoven wire filaments comprising the support member and which correspondto the surface aberrations after removal of the web.

U.S. Pat. No. 5,733,628 discloses a film laminate wherein the carriermaterial comprises a woven or non-woven fibrous material and anelastomeric three-dimensional apertured film.

Non-apertured surface structured films include films with solid or withhollow surface structures.

According to U.S. Pat. No. 5,814,413 surface-texturing of a polymer filmis accomplished by taking advantage of the usually undesired phenomenonof melt fracture. The patent discloses extruded films which due to meltfracture show a rough surface texture.

International Patent Application WO 97/02128 provides a process forproducing a surface-structured, sheet-like semi-finished product madefrom thermoplastic polymers. The resulting product is reported to have avelour-like or velvety surface with numerous solid fibrous projectionswhich can be longer than 3 millimeters. According to the disclosedprocess, the thermoplastic material is extruded in the molten state ontoa moving belt or roller surface which is covered with cavities orborings having a depth of between 2 and 4 millimeters. The rollersurface is exposed to a vacuum from the outside thus removing the airfrom the cavities and enabling these to be filled with the thermoplasticmaterial. After solidification of the thermoplastic material, thesemi-finished product covered with fiber-like projections is peeled offthe surface.

International Patent Application WO 99/47339 describes a method forproducing a surface-structured, film-like semi-finished product from athermoplastic comprising forming a pile consisting of solidprotuberances and elongating the protruberances by combing, brushing,knife-coating and/or shear pinching.

International Patent Application WO 99/16608 discloses a method formaking an embossed oriented film. Said method discloses the steps ofsoftening at least one of the two major surfaces of an oriented film,embossing the softened surface(s), and cooling the resulting embossedoriented thermoplastic film. In order to maintain orientation thecombined steps of softening, embossing and cooling should occur within asecond.

International Patent Application WO 99/06623 provides a unitary polymersubstrate having a plurality of solid microfibers which may have avariety of forms, such as frayed-end microfibers, tapered microfibers,microfibers having an expanded cross-sectional shape and microfibershaving a high aspect ratio. The microfibers are reported to increase thesurface area and to impart a cloth-like feel.

International Patent Application WO 00/16965 relates to a method forproducing a surface-structured, film-like semifinished product made of athermoplastic which is applied onto a surface covered with finecavities. The solidified plastic is removed from the surface as astructured film. The disclosed structure is a pile comprised of solidprojections and naps which may be stretched, e.g. by brushing.

Films with bubble-like surface features which are hollow from the bottomare disclosed, for example, in U.S. Pat. No. 4,463,045, InternationalPatent Application WO 96/13979 and U.S. Pat. No. 5,192,484.

U.S. Pat. No. 5,792,411 suggests replicated articles with surfacestructures which have a suction cup geometric configuration.

There still is the need for plastic articles showing improvedproperties, particularly excellent aesthetics, as reflected in atextile-like haptic appearance and low gloss. Further representativeproperties desirable for plastic articles include, for example,increased surface area, variability of the surface appearance, anti-slipbehavior, controlled storage, release or carrier properties, controlledthermal and barrier performance, as well as any combination thereof.

It is an object of the present invention to meet these needs. It is anobject of the present invention to provide surface-structured plasticfilms, sheets or coatings with hollow surface structures which can bespecifically designed to meet the desired performance attribute(s) andcan be produced in a cost effective way. In particular, it is one objectof the present invention to provide a plastic article having a soft,velvety and cloth-like touch in combination with a mat appearance. It isanother object to provide a plastic article having an increased surfacearea. It is yet a further object of the present invention to provide aplastic article with an imprintable surface. The present invention alsoaddresses the problem of providing a plastic article having a frictionalbehavior indicating anti-slip properties. It is a particular object ofthe present invention to provide a plastic article, which displays anydesired combination of the above-mentioned properties, and may affordadditional advantageous performance attributes depending on the intendedend-use application(s).

The objects of the present invention are achieved by providing a film,sheet, or coating, which is characterized by a distinct morphology. Suchmorphology is reflected in the presence of at least one layer having afringed surface microstructure and, optionally, of further layersaffording certain additional functions, for example, heat sealability,bulk or mechanical properties. The morphology and composition of thefilm, sheet or coating of the invention can be tailored to satisfy theparticular requirements of the production process and the intendedend-use application(s).

SUMMARY OF THE INVENTION

The present invention pertains to a mono-layer or multi-layer film,sheet, or coating. The film, sheet or coating of the invention comprisesat least one layer which is a thermoplastic polymeric material and whichis characterized by a fringed surface microstructure. The fringes ofsaid microstructure are non-perforated crater-like peaks which are atleast partially hollow. The density of the fringes is at least 1000 persquare centimeter, or higher. The layer may be covered by the fringedsurface microstructure in its entirety, or in part, e.g. in one area orin several areas. The fringed surface microstructure may be discerniblewith the naked eye or on appropriate magnification.

Another aspect of the invention relates to a composite comprising amono-layer or multi-layer film, sheet, or coating based on athermoplastic polymeric material wherein at least one layer has afringed surface microstructure.

Another aspect of the invention relates to an article of manufacturecomprising or made from a mono-layer or multi-layer film, sheet, orcoating based on a thermoplastic polymeric material wherein at least onelayer has a fringed surface microstructure.

Another aspect of the invention relates to a process for making thefilm, sheet, or coating based on a thermoplastic polymeric materialwherein at least one layer has a fringed surface microstructure, saidprocess comprising:

-   -   providing a precursor film, sheet, or coating with a surface        characterized by a pattern of peaks and valleys, and    -   treating said precursor such as to create a surface having a        fringed microstructure.

Preferably, the treatment is mechanical in nature.

Yet another aspect of the invention relates to the use of a mono- ormultilayer film, sheet, or coating which is based on a thermoplasticpolymeric material and wherein at least one layer has or comprises thefringed surface microstructure in applications or articles which benefitfrom the advantageous properties and performance attributes provided bythe fringed surface microstructure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exemplary individual fringe and selected parameterscharacterizing its three-dimensional structure.

FIG. 2 shows an example of a device suitable to make a film, sheet orcoating having a fringed microstructure.

FIG. 3 illustrates a method to determine the release angle at which thefilm, sheet or coating is stripped from the matrix roll in a calendersuitable to make the film, sheet or coating having the fringed surfacemicrostructure.

DETAILED DESCRIPTION OF THE INVENTION

Basic Definitions

The term “film” as used herein refers to a thin article and includesstrips, tapes, and ribbons. The article has a flat form and a thicknessof about 10 mils (250 microns (μm) or micrometer), or less. Thicknessdata for a film having a fringed surface microstructure generallyexclude the fringe height.

The term “sheet” as used herein refers to a flat article having athickness of greater than about 10 mils (250 microns).

The term “coating” as used herein refers to a material applied over oron top of a substrate material. The substrate material (or its surface)can be of any shape, form or contour. For example, a film, profile ormolding may be coated or comprise a coating. Also, the substrate surfacecan be made from a thermoplastic or a non-thermoplastic material suchas, for example, but not limited to, polyethylene, polypropylene, paper,glass, ceramic, cardboard, foil, wood or wood-based materials, such asparticleboard or fiberboard, and metal, such as copper.

The term “multi-layer film, sheet, or coating” (including eachindividually e.g. “multi-layer film”) as used herein indicates a film,sheet, or coating consisting of two, three, four, five, six, seven ormore layers.

The term “foamed film, sheet, or coating” (including each individuallye.g. “foamed film”) as used herein refers to a mono-layer or multi-layerstructure wherein at least one layer of the structure is foamed and hasa density less than the non-foamed polymer.

The term “composite” as used herein refers to a multi-layer ormulti-component article or material comprising at least one film, sheet,or coating layer having a fringed surface structure, (including, forexample, but not limited to, a fabric or a laminated structure which maycomprise, for example foil or paper).

The term “polymeric material” as used herein refers to a polymericcompound obtainable by polymerizing one or more monomers. The genericterm “polymeric compound” or “polymer” is intended to include ahomopolymer, usually employed to refer to polymers prepared from onlyone monomer, and an interpolymer as defined hereinafter.

The term “comprising” as used herein means “including”.

The term “interpolymer” as used herein refers to polymers prepared bythe polymerization of at least two monomers. The generic terminterpolymer thus embraces the terms copolymer, usually employed torefer to polymers prepared from two different monomers, and polymersprepared from more than two different monomers, such as terpolymers.

Unless specified otherwise, the term “alpha-olefin” (“α-olefin”) as usedherein refers to an aliphatic or cyclo-aliphatic alpha-olefin having atleast 3, preferably 3 to 20 carbon atoms.

Unless indicated to the contrary, all parts, percentages and ratios areby weight. The expression “up to” when used to specify a numerical rangeincludes any value less than or equal to the numerical value whichfollows this expression. The expressions “cc” or “ccm” stand for “cubiccentimeters”.

Thermoplastic Materials

The film, sheet, or coating of the invention is based on or made fromone or more thermoplastic polymeric materials, including, for example,latex. Preferred thermoplastic polymeric materials are semicrystallinepolymers, amorphous polymers, or blends thereof. Advantageously,suitable thermoplastic polymers may be selected from the groupconsisting of polyolefins, poly(lactide), alkenyl aromatic polymers,thermoplastic polyurethanes, polycarbonates, polyamides, polyethers,thermoplastic phenoxy resins, polyvinyl chloride polymers,polyvinylidene chloride polymers and polyesters, including certainelastomers and block polymers. Semicrystalline thermoplastic materialsand blends thereof are preferred.

Suitable polyolefins include, for example, ethylene-based polymers,including ethylene homopolymer and interpolymer, aliphatic alpha-olefinhomopolymers, such as polypropylene, polybutene and polyisoprene, andtheir interpolymers.

Ethylene homopolymers, for example low density polyethylene (LDPE) andhigh density polyethylene (HDPE), and ethylene interpolymers are knownclasses of thermoplastic polymers, each having many members. They areprepared by homopolymerizing ethylene or interpolymerizing (for example,copolymerizing) ethylene with one or more vinyl- or diene-basedcomonomers, for example, α-olefins of 3 to about 20 carbon atoms, vinylesters, vinyl acids, styrene-based monomers, monomers containing two ormore sites of ethylenic unsaturation, etc., using known copolymerizationreactions and conditions.

Ethylene (based) polymers suitable for use in the present inventioninclude both homogeneously branched (homogeneous) polymers andheterogeneously branched (heterogeneous) polymers.

Homogeneous polymers encompass ethylene-based interpolymers in which anycomonomer is randomly distributed within a given interpolymer moleculeand substantially all of the interpolymer molecules have the sameethylene/comonomer ratio within that interpolymer. Homogeneous ethylenepolymers generally are characterized as having an essentially singlemelting (point) peak between −30° C. and 150° C., as determined bydifferential scanning calorimetry (DSC). The single melting peak may berelatively broad, such as is the case when an ethylene polymer having acrystallinity of less than about 36 percent is employed. The singlemelting peak may be sharp, such as is the case when an ethylene polymerhaving a crystallinity of at least about 36 percent is employed.

Typically, homogeneous ethylene polymers will also have a relativelynarrow molecular weight distribution (MWD) as compared to correspondingheterogeneous ethylene polymers. Preferably, the molecular weightdistribution defined as the ratio of weight average molecular weight tonumber average molecular weight (M_(w)/M_(n)), is less than about 3.5(when the density of the interpolymer is less than about 0.960 g/cc),more preferably less than about 3.0.

In addition or in the alternative, the homogeneity of the ethylene-basedpolymers is reflected in a narrow composition distribution, which can beexpressed using parameters such SCBDI (Short Chain Branch DistributionIndex) or (CDBI Composition Distribution Branch Index). The SCBDI of apolymer is readily calculated from data obtained from techniques knownin the art, such as, for example, temperature rising elutionfractionation (abbreviated herein as “TREF”) as described, for example,in Wild et al, Journal of Polymer Science, Poly. Phys. Ed., Vol. 20, p.441 (1982), in U.S. Pat. No. 4,798,081 (Hazlitt et al.), or in U.S. Pat.No. 5,089,321 (Chum et al.), the disclosures of all of which areincorporated herein by reference. CDBI is defined as the weight percentof the polymer molecules having a comonomer content within 50 percent ofthe median total molar comonomer content. The SCBDI or CDBI for thehomogeneous linear and substantially linear ethylene/alpha-olefinpolymers used in the present invention is typically greater than about50 percent.

The homogeneous ethylene polymers that can be used in the presentinvention fall into two broad categories, the linear homogeneousethylene polymers and the substantially linear homogeneous ethylenepolymers. Both are known.

Homogeneous linear ethylene polymers have long been commerciallyavailable. As exemplified in U.S. Pat. No. 3,645,992 to Elston,homogeneous linear ethylene polymers can be prepared in conventionalpolymerization processes using Ziegler-type catalysts such as, forexample, zirconium and vanadium catalyst systems. U.S. Pat. No.4,937,299 to Ewen et al. and U.S. Pat. No. 5,218,071 to Tsutsui et al.disclose the use of metallocene catalysts, such as catalyst systemsbased on hafnium, for the preparation of homogeneous linear ethylenepolymers. Commercially available examples of homogeneous linear ethylenepolymers include, for example, those sold by Mitsui PetrochemicalIndustries as TAFMER™ resins and by Exxon Chemical Company as EXACT™ andEXCEED™ resins.

The substantially linear ethylene polymers (SLEPs) are homogeneouspolymers having long chain branching.

The term “substantially linear ethylene polymer” as used herein meansthat the bulk ethylene polymer is substituted, on average, with about0.01 long chain branches/1000 total carbons to about 3 long chainbranches/1000 total carbons (wherein “total carbons” includes bothbackbone and branch carbon atoms). Preferred polymers are substitutedwith about 0.01 long chain branches/000 total carbons to about 1 longchain branches/1000 total carbons, more preferably from about 0.05 longchain branches/1000 total carbons to about 1 long chain branched/1000total carbons, and especially from about 0.3 long chain branches/1000total carbons to about 1 long chain branches/1000 total carbons.

As used herein, the term “backbone” refers to a discrete molecule, andthe term “polymer” or “bulk polymer” refers, in the conventional sense,to the polymer as formed in a reactor. For the polymer to be a“substantially linear ethylene polymer”, the polymer must have at leastenough molecules with long chain branching such that the average longchain branching in the bulk polymer is at least an average of from about0.01/1000 total carbons to about 3 long chain branches/1000 totalcarbons.

The term “bulk polymer” as used herein means the polymer which resultsfrom the polymerization process as a mixture of polymer molecules and,for substantially linear ethylene polymers, includes molecules having anabsence of long chain branching as well as molecules having long chainbranching. Thus a “bulk polymer” includes all molecules formed duringpolymerization. It is understood that, for the substantially linearpolymers, not all molecules have long chain branching, but a sufficientamount do such that the average long chain branching content of the bulkpolymer positively affects the melt rheology (i.e., the melt fractureproperties) as described herein below and elsewhere in the literature.

Long chain branching (LCB) is defined herein as a chain length of atleast one (1) carbon (atom) less than the number of carbons in thecomonomer, whereas short chain branching (SCB) is defined herein as achain length of the same number of carbons in the residue of thecomonomer after it is incorporated into the polymer molecule backbone.For example, a substantially linear ethylene/1-octene polymer hasbackbones with long chain branches of at least seven (7) carbons inlength, but it also has short chain branches of only six (6) carbons inlength.

Long chain branching can be distinguished from short chain branching byusing ¹³C nuclear magnetic resonance (NMR) spectroscopy and to a limitedextent, e.g. for ethylene homopolymers, it can be quantified using themethod of Randall, (Rev. Macromol. Chem. Phys., C29 (2&3), p. 285-297),the disclosure of which is incorporated herein by reference. However asa practical matter, current ¹³C nuclear magnetic resonance spectroscopycannot determine the length of a long chain branch in excess of aboutsix (6) carbon atoms and as such, this analytical technique cannotdistinguish between a seven (7) carbon branch and a seventy (70) carbonbranch. The long chain branch can be as long as about the same length asthe length of the polymer backbone.

Although conventional ¹³C nuclear magnetic resonance spectroscopy cannotdetermine the length of a long chain branch in excess of six carbonatoms, there are other known techniques useful for quantifying ordetermining the presence of long chain branches in ethylene polymers,including ethylene/1-octene interpolymers. For example, U.S. Pat. No.4,500,648, incorporated herein by reference, teaches that long chainbranching frequency (LCB) can be represented by the equation LCB=b/M_(w)wherein b is the weight average number of long chain branches permolecule and M_(w) is the weight average molecular weight. The molecularweight averages and the long chain branching characteristics aredetermined by gel permeation chromatography and intrinsic viscositymethods, respectively.

Two other useful methods for quantifying or determining the presence oflong chain branches in ethylene polymers, including ethylene/1-octeneinterpolymers are gel permeation chromatography coupled with a low anglelaser light scattering detector (GPC-LALLS) and gel permeationchromatography coupled with a differential viscometer detector (GPC-DV).The use of these techniques for long chain branch detection and theunderlying theories have been well documented in the literature. See,e.g., Zimm, G. H. and Stockmayer, W. H., J. Chem. Phys., 17, 1301 (1949)and Rudin, A., Modern Methods of Polymer Characterization, John Wiley &Sons, New York (1991) pp. 103-112, the disclosures of both of which areincorporated by reference.

A. Willem deGroot and P. Steve Chum, both of The Dow Chemical Company,at the Oct. 4, 1994 conference of the Federation of Analytical Chemistryand Spectroscopy Society (FACSS) in St. Louis, Mo., presented datademonstrating that GPC-DV is indeed a useful technique for quantifyingthe presence of long chain branches in substantially linear ethylenepolymers. In particular, deGroot and Chum found that the level of longchain branches in substantially linear ethylene homopolymer samplesmeasured using the Zimm-Stockmayer equation correlated well with thelevel of long chain branches measured using ¹³C NMR.

Further, deGroot and Chum found that the presence of octene does notchange the hydrodynamic volume of the polyethylene samples in solutionand, as such, one can account for the molecular weight increaseattributable to octene short chain branches by knowing the mole percentoctene in the sample. By deconvoluting the contribution to molecularweight increase attributable to 1-octene short chain branches, deGrootand Chum showed that GPC-DV may be used to quantify the level of longchain branches in substantially linear ethylene/octene copolymers.

DeGroot and Chum also showed that a plot of log(I₂, melt index) as afunction of log(GPC Weight Average Molecular Weight) as determined byGPC-DV Illustrates that the long chain branching aspects (but not theextent of long branching) of substantially linear ethylene polymers arecomparable to that of high pressure, highly branched low densitypolyethylene (LDPE) and are clearly distinct from ethylene polymersproduced using Ziegler-type catalysts such as titanium complexes andordinary homogeneous catalysts such as hafnium and vanadium complexes.

For substantially linear ethylene polymers, the empirical effect of thepresence of long chain branching is manifested as enhanced rheologicalproperties which are quantified and expressed in terms of gas extrusionrheometry (GER) results and/or melt flow, I₁₀/I_(2′) increases.

The substantially linear ethylene polymers suitable for the purpose ofthe present invention are a unique class of compounds that are furtherdefined in U.S. Pat. No. 5,272,236, U.S. Pat. No. 5,278,272, and U.S.Pat. No. 5,665,800, each of which is incorporated herein by reference.SLEPs are available from The Dow Chemical Company as polymers made bythe INSITE™ Process and Catalyst Technology, such as AFFINITY™polyolefin plastomers (POPs), and from DuPont Dow Elastomers, L.L.C. asENGAGE™ polyolefin elastomers (POEs).

Substantially linear ethylene polymers differ significantly from theclass of polymers conventionally known as homogeneously branched linearethylene polymers described above. As an important distinction,substantially linear ethylene polymers do not have a linear polymerbackbone in the conventional sense of the term “linear” as is the casefor homogeneously branched linear ethylene polymers. Substantiallylinear ethylene polymers also differ significantly from the class ofpolymers known conventionally as heterogeneously branched traditionalZiegler polymerized linear ethylene interpolymers (for example, ultralow density polyethylene, linear low density polyethylene (LLDPE) orhigh density polyethylene (HDPE) made, for example, using the techniquedisclosed by Anderson et al. in U.S. Pat. No. 4,076,698, in thatsubstantially linear ethylene interpolymers are homogeneously branchedpolymers; that is, substantially linear ethylene polymers have a SCBDIgreater than or equal to 50 percent, preferably greater than or equal to70 percent, more preferably greater than or equal to 90 percent.Substantially linear ethylene polymers also differ from the class ofheterogeneously branched ethylene polymers in that substantially linearethylene polymers are characterized as essentially lacking a measurablehigh density or crystalline polymer fraction as determined using atemperature rising elution fractionation technique.

The substantially linear ethylene polymer for use in the presentinvention can be characterized as having

-   -   (a) melt flow ratio, I₁₀/I₂·5.63,    -   (b) a molecular weight distribution, M_(w)/M_(n), as determined        by gel permeation chromatography and defined by the equation:        (M_(w)/M_(n))≦(I₁₀/I₂)−4.63,    -   (c) a gas extrusion rheology such that the critical shear rate        at onset of surface melt fracture for the substantially linear        ethylene polymer is at least 50 percent greater than the        critical shear rate at the onset of surface melt fracture for a        linear ethylene polymer, wherein the substantially linear        ethylene polymer and the linear ethylene polymer comprise the        same comonomer or comonomers, the linear ethylene polymer has an        I₂ and M_(w)/M_(n) within ten percent of the substantially        linear ethylene polymer and wherein the respective critical        shear rates of the substantially linear ethylene polymer and the        linear ethylene polymer are measured at the same melt        temperature using a gas extrusion rheometer,    -   (d) a single differential scanning calorimetry, DSC, melting        peak between −30° C. and 150° C., and    -   (e) a short chain branching distribution index greater than 50        percent.

Determination of the critical shear rate and critical shear stress inregards to melt fracture as well as other rheology properties such as“rheological processing index” (PI), is performed using a gas extrusionrheometer (GER). The gas extrusion rheometer is described by M. Shida,R. N. Shroff and L. V. Cancio in Polymer Engineering Science. Vol. 17,No. 11, p. 770 (1977) and in Rheometers for Molten Plastics by JohnDealy, published by Van Nostrand Reinhold Co. (1982) on pp. 97-99, thedisclosures of both of which are incorporated herein by reference.

The processing index (PI) is measured at a temperature of 190° C., atnitrogen pressure of 2500 psig using a 0.0296 inch (752 micrometers)diameter (preferably a 0.0143 inch diameter die for high flow polymers,e.g. 50-100 I₂ melt index or greater), 20:1 L/D die having an entranceangle of 180°. The GER processing index is calculated in millipoiseunits from the following equation:PI=2.15×10⁶ dyne/cm²/(1000×shear rate),

-   -   wherein: 2.15×10⁶ dyne/cm² is the shear stress at 2500 psi, and        the shear rate is the shear rate at the wall as represented by        the following equation:        32 Q′/(60 sec/min)(0.745)(Diameter×2.54 cm/in)³,        wherein:    -   Q′ is the extrusion rate (gms/min),    -   0.745 is the melt density of polyethylene (gm/cm³), and    -   Diameter is the orifice diameter of the capillary (inches).

The PI is the apparent viscosity of a material measured at apparentshear stress of 2.15×10⁶ dyne/cm².

For substantially linear ethylene polymers, the PI is less than or equalto 70 percent of that of a conventional linear ethylene polymer havingan I₂, M_(w)/M_(n) and density each within ten percent of thesubstantially linear ethylene polymer.

An apparent shear stress vs. apparent shear rate plot is used toidentify the melt fracture phenomena over a range of nitrogen pressuresfrom 5250 to 500 psig using the die or GER test apparatus previouslydescribed. According to Ramamurthy in Journal of Rheology, 30(2),337-357, 1986, above a certain critical flow rate, the observedextrudate irregularities may be broadly classified into two main types:surface melt fracture and gross melt fracture.

Surface melt fracture occurs under apparently steady flow conditions andranges in detail from loss of specular gloss to the more severe form of“sharkskin”. In this disclosure, the onset of surface melt fracture ischaracterized at the beginning of losing extrudate gloss at which thesurface roughness of extrudate can only be detected by 40×magnification. The critical shear rate at onset of surface melt fracturefor the substantially linear ethylene polymers is at least 50 percentgreater than the critical shear rate at the onset of surface meltfracture of a linear ethylene polymer having about the same I₂ andM_(w)/M_(n). Preferably, the critical shear stress at onset of surfacemelt fracture for the substantially linear ethylene polymers of theinvention is greater than about 2.8×10⁶ dyne/cm².

Gross melt fracture occurs at unsteady flow conditions and ranges indetail from regular (alternating rough and smooth, helical, etc.) torandom distortions. For commercial acceptability, (e.g., in blown filmproducts), surface defects should be minimal, if not absent. Thecritical shear rate at onset of surface melt fracture (OSMF) andcritical shear stress at onset of gross melt fracture (OGMF) will beused herein based on the changes of surface roughness and configurationsof the extrudates extruded by a GER. For the substantially linearethylene polymers used in the invention, the critical shear stress atonset of gross melt fracture is preferably greater than about 4×10⁶dyne/cm².

For the processing index determination and for the GER melt fracturedetermination, substantially linear ethylene polymers are tested withoutinorganic fillers and do not have more than 20 ppm aluminum catalystresidue. Preferably, however, for the processing index and melt fracturetests, substantially linear ethylene polymers do contain antioxidantssuch as phenols, hindered phenols, phosphites or phosphonites,preferably a combination of a phenol or hindered phenol and a phosphiteor a phosphonite.

The molecular weight distributions of ethylene polymers are determinedby gel permeation chromatography (GPC) on a Waters 150° C. hightemperature chromatographic unit equipped with a differentialrefractometer and three columns of mixed porosity. The columns aresupplied by Polymer Laboratories and are commonly packed with pore sizesof 10³, 10⁴, 10⁵ and 10⁶ Å. The solvent is 1,2,4-trichlorobenzene, fromwhich about 0.3 percent by weight solutions of the samples are preparedfor injection. The flow rate is about 1.0 milliliters/minute, unitoperating temperature is about 140° C. and the injection size is about100 microliters.

The molecular weight determination with respect to the polymer backboneis deduced by using narrow molecular weight distribution polystyrenestandards (from Polymer Laboratories) in conjunction with their elutionvolumes. The equivalent polyethylene molecular weights are determined byusing appropriate Mark-Houwink coefficients for polyethylene andpolystyrene (as described by Williams and Ward in Journal of PolymerScience, Polymer Letters, Vol. 6, p. 621, 1968, the disclosure of whichis incorporated herein by reference) to derive the following equation:M_(polyethylene) =a·(M_(polystyrene))^(b)

In this equation, a=0.4316 and b=1.0. Weight average molecular weight,M_(w), is calculated in the usual manner according to the followingformula:Mj=(Σw_(i)(M_(i) ^(l)))^(j);wherein w_(i) is the weight fraction of the molecules with molecularweight M_(i) eluting from the GPC column in fraction i and j=1 whencalculating M_(w) and j=−1 when calculating M_(n).

Substantially linear ethylene polymers are known to have excellentprocessability, despite having a relatively narrow molecular weightdistribution (that is, the M_(w)/M_(n) ratio is typically less thanabout 3.5). Surprisingly, unlike homogeneously and heterogeneouslybranched linear ethylene polymers, the melt flow ratio (I₁₀/I₂) ofsubstantially linear ethylene polymers can be varied essentiallyindependently of the molecular weight distribution, M_(w)/M_(n).

Suitable constrained geometry catalysts for manufacturing substantiallylinear ethylene polymers include constrained geometry catalysts asdisclosed in U.S. application Ser. No. 07/545,403, filed Jul. 3, 1990;U.S. application Ser. No. 07/758,654, filed Sep. 12, 1991; U.S. Pat. No.5,132,380; U.S. Pat. No. 5,064,802; U.S. Pat. No. 5,470,993; U.S. Pat.No. 5,453,410; U.S. Pat. No. 5,374,696; U.S. Pat. No. 5,532,394; U.S.Pat. No. 5,494,874; and U.S. Pat. No. 5,189,192, the teachings of all ofwhich are incorporated herein by reference.

Suitable catalyst complexes may also be prepared according to theteachings of WO 93/08199, and the patents issuing therefrom, all ofwhich are incorporated herein by reference. Further, themonocyclopentadienyl transition metal olefin polymerization catalyststaught in U.S. Pat. No. 5,026,798, which is incorporated herein byreference, are also believed to be suitable for use in preparing thepolymers of the present invention, so long as the polymerizationconditions substantially conform to those described in U.S. Pat. No.5,272,236; U.S. Pat. No. 5,278,272 and U.S. Pat. No. 5,665,800,especially with strict attention to the requirement of continuouspolymerization. Such polymerization methods are also described in PCT/US92/08812 (filed Oct. 15, 1992).

The foregoing catalysts may be further described as comprising a metalcoordination complex comprising a metal of groups 3-10 or the Lanthanideseries of the Periodic Table of the Elements and a delocalize β-bondedmoiety substituted with a constrain-inducing moiety, said complex havinga constrained geometry about the metal atom such that the angle at themetal between the centroid of the delocalized, substituted pi-bondedmoiety and the center of at least one remaining substituent is less thansuch angle in a similar complex containing a similar pi-bonded moietylacking in such constrain-inducing substituent, and provided furtherthat for such complexes comprising more than one delocalized,substituted pi-bonded moiety, only one thereof for each metal atom ofthe complex is a cyclic, delocalized, substituted pi-bonded moiety. Thecatalyst further comprises an activating cocatalyst.

Suitable cocatalysts for use herein include polymeric or oligomericaluminoxanes, especially methyl aluminoxane, as well as inert,compatible, noncoordinating, ion forming compounds. So called modifiedmethyl aluminoxane (MMAO) is also suitable for use as a cocatalyst. Onetechnique for preparing such modified aluminoxane is disclosed in U.S.Pat. No. 5,041,584, the disclosure of which is incorporated herein byreference. Aluminoxanes can also be made as disclosed in U.S. Pat. No.5,218,071; U.S. Pat. No. 5,086,024; U.S. Pat. No. 5,041,585; U.S. Pat.No. 5,041,583; U.S. Pat. No. 5,015,749; U.S. Pat. No. 4,960,878; andU.S. Pat. No. 4,544,762, the disclosures of all of which areincorporated herein by reference.

Aluminoxanes, including modified methyl aluminoxanes, when used in thepolymerization, are preferably used such that the catalyst residueremaining in the (finished) polymer is preferably in the range of fromabout 0 to about 20 ppm aluminum, especially from about 0 to about 10ppm aluminum, and more preferably from about 0 to about 5 ppm aluminum.In order to measure the bulk polymer properties (e.g. PI or meltfracture), aqueous HCl is used to extract the aluminoxane from thepolymer. Preferred cocatalysts, however, are inert, noncoordinating,boron compounds such as those described in EP-A-0520732, the disclosureof which is incorporated herein by reference.

Substantially linear ethylene are produced via a continuous (as opposedto a batch) controlled polymerization process using at least one reactor(e.g., as disclosed in WO 93107187, WO 93107188, and WO 93/07189, thedisclosure of each of which is incorporated herein by reference), butcan also be produced using multiple reactors (e.g., using a multiplereactor configuration as described in U.S. Pat. No. 3,914,342, thedisclosure of which is incorporated herein by reference) at apolymerization temperature and pressure sufficient to produce theinterpolymers having the desired properties. The multiple reactors canbe operated in series or in parallel, with at least one constrainedgeometry catalyst employed in at least one of the reactors.

Substantially linear ethylene polymers can be prepared via thecontinuous solution, slurry, or gas phase polymerization in the presenceof a constrained geometry catalyst, such as the method disclosed inEP-A416,815, the disclosure of which is incorporated herein byreference. The polymerization can generally be performed in any reactorsystem known in the art including, but not limited to, a lankreactor(s), a sphere reactor(s), a recycling loop reactor(s) orcombinations thereof and the like, any reactor or all reactors operatedpartially or completely adiabatically, nonadiabatically or a combinationof both and the like. Preferably, a continuous loop-reactor solutionpolymerization process is used to manufacture the substantially linearethylene polymer used in the present invention.

In general, the continuous polymerization required to manufacturesubstantially linear ethylene polymers may be accomplished at conditionswell known in the prior art for Ziegler-Natta or Kaminsky-Sinn typepolymerization reactions, that is, temperatures from 0 to 250° C. andpressures from atmospheric to 1000 atmospheres (100 MPa). Suspension,solution, slurry, gas phase or other process conditions may be employedif desired.

A support may be employed in the polymerization, but preferably thecatalysts are used in a homogeneous (i.e., soluble) manner. It will, ofcourse, be appreciated that the active catalyst system forms in situ ifthe catalyst and the cocatalyst components thereof are added directly tothe polymerization process and a suitable solvent or diluent, includingcondensed monomer, is used in said polymerization process. It is,however, preferred to form the active catalyst in a separate step in asuitable solvent prior to adding the same to the polymerization mixture.

Preferably, the substantially linear ethylene polymers used in thepresent invention are interpolymers of ethylene with at least one C₃-C₂₀α-olefin and/or C₄C₁₈ diolefin, in accordance with the definitions andpreferences given hereinbelow. Copolymers of ethylene and an α-olefin ofC₃-C₂₀ carbon atoms are preferred.

Heterogeneous ethylene-based polymers encompass ethylene/α-olefininterpolymers characterized as having a linear backbone and a DSCmelting curve having a distinct melting point peak greater than 115° C.attributable to a high density fraction. Such heterogeneousinterpolymers win typically have a broader molecular weight distributionthan homogeneous interpolymers, as reflected in a M_(w)/M_(n) ratio ofgreater than about 3.5 (when the density of the interpolymer is lessthan about 0.960 g/cc). Typically, heterogeneous ethylene interpolymershave a CDBI of about 50% or less, indicating that such interpolymers area mixture of molecule having differing comonomer contents and differingamounts of short chain branching.

The heterogeneous ethylene polymers that can be used in the of thisinvention fall into two broad categories, those prepared with a freeradical initiator at high temperature and high pressure, and thoseprepared-with a coordination catalyst at high temperature and relativelylow pressure. The former are generally known as low densitypolyethylenes (LDPE) and are characterized by branched chains ofpolymerized monomer units pendant from the polymer backbone. LDPEpolymers generally have a density between about 0.910 and 0.935 g/cc.Ethylene polymers and copolymer prepare by the use of a coordinationcatalyst, such as a Ziegler or Phillips catalyst, are generally known aslinear polymers because of the substantial absence of branch chains ofpolymerized monomer units pendant from the backbone. High densitypolyethylene (HDPE), generally having a density of about 0.941 to about0.965 g/cc, is typically a homopolymer of ethylene, and it containsrelatively few branch chains relative to the various linear copolymersof ethylene and an α-olefin. HDPE is well known, commercially availablein various grades, and may be used in this invention.

Linear copolymers of ethylene and at least one α-olefin of 3 to 12carbon atoms, preferably of 4 to 8 carbon atoms, are also well known andcommercially available. As is well known in the art, the density of alinear ethylene/α-olefin copolymer is a function of both the length ofthe α-olefin and the amount of such monomer in the copolymer relative tothe amount of ethylene, the greater the length of the α-olefin and thegreater the amount of α-olefin present, the lower the density of thecopolymer. Linear low density polyethylene (LLDPE) is typically acopolymer of ethylene and an α-olefin of 3 to 12 carbon atoms,preferably 4 to 8 carbon atoms (for example, 1-butene, 1-octene, etc.),that has sufficient α-olefin content to reduce the density of thecopolymer to that of LDPE. When the copolymer contains even moreα-olefin, the density will drop below about 0.91 g/cc and thesecopolymers are known as ultra low density polyethylene (ULDPE) or verylow density polyethylene (VLDPE). The densities of these linear polymersgenerally range from about 0.87 g/cc to about 0.91 g/cc.

Both the materials made by the free radical catalysts and by thecoordination catalysts are well known in the art, as are their methodsof preparation. For example, heterogeneous linear ethylene polymers areavailable from The Dow Chemical Company as DOWLEX™ LLDPE polymers and asATTANE™ ULDPE resins. Heterogeneous linear ethylene polymers can beprepared via the solution, slurry or gas phase polymerization ofethylene and one or more optional α-olefin comonomers in the presence ofa Ziegler Natta catalyst, by processes such as are disclosed in U.S.Pat. No. 4,076,698 to Anderson et al., which is incorporated herein byreference.

As indicated above, the ethylene polymers suitable for the purpose ofthe present invention can be interpolymers of ethylene and at least oneα-olefin. Suitable α-olefins for use as comonomers in a solution, gasphase or slurry polymerization process or combinations thereof include1-propylene, 1-butene, 1-isobutylene, 1-pentene, 1-hexene,4-methyl-1-pentene, 1-heptene and 1-octene, as well as other monomertypes such as tetrafluoroethylene, vinyl benzocyclobutane,1,4-hexadiene, 1,7-octadiene, and cycloalkenes, for examplecyclopentene, cyclohexene, cyclooctene, norbornene (NB), and ethylidenenorbornene (ENB)). Preferably, the α-olefin will be 1-butene, 1-pentene,4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, NB or ENB, ormixtures thereof. More preferably, the α-olefin will be 1-pentene,1-hexene, 1-heptene, 1-octene, or mixtures thereof. Most preferably, theα-olefin will be 1-octene.

Ethylene/α-olefin/diene terpolymers may also be used as elastomericpolymers in this invention. Suitable α-olefins include the c-olefinsdescribed above as suitable for making ethylene α-olefin copolymers. Thedienes suitable as monomers for the preparation of such terpolymers aretypically non-conjugated dienes having from 6 to 15 carbon atoms.Representative examples of suitable non-conjugated dienes that may beused to prepare the terpolymer include:

-   -   a) Straight chain acyclic dienes such as 1,4-hexadiene,        1,5-heptadiene, and 1,6-octadiene;    -   b) branched chain acyclic dienes such as 5-methyl-1,4-hexadiene,        3,7-dimethyl-1-6-octadiene, and 3,7-dimethyl-1,7-octadiene;    -   c) single ring alicyclic dienes such as 4-vinylcyclohexene,        1-allyl-4-isopropylidene cyclohexane, 3-allylcyclopentene,        4-allylcyclohexene, and 1-isopropenyl-4-butenylcyclohexane;    -   d) multi-ring alicyclic fused and bridged ring dienes such as        dicyclopentadiene; alkenyl, alkylidene, cycloalkenyl and        cycloalkylidene norbomenes such as 5-methylene-2-norbornene,        5-methylene-6-methyl-2-norbornene,        5-methylene-6,6-dimethyl-2-norbornene, 5-propenyl-2-norbornene,        5-(3-cyclopentenyl)-2-norbornene, 5-ethylidene-2-norbornene,        5-cyclohexylidene-2-norbornene, etc.

The preferred dienes are selected from the group consisting of1,4-hexadiene, dicyclopentadiene, 5-ethylidene-2-norbornene,5-methylene-2-norbornene, 7-methyl-1,6-octadiene, piperylene,4-vinylcyclohexene, etc.

The preferred terpolymers for the practice of the invention areterpolymers of ethylene, propylene and a non-conjugated diene (EPDM).Such terpolymers are commercially available. Ethylene/α-olefin/dieneterpolymers are useful when it is desired to make elastomeric polymerblends vulcanizable with the well known sulfur compound vulcanizationprocess.

Ethylene/unsaturated carboxylic acid, salt and ester interpolymers mayalso be used in this invention. These are interpolymers of ethylene withat least one comonomer selected from the group consisting of vinylesters of a saturated carboxylic acid wherein the acid moiety has up to4 carbon atoms, unsaturated mono- or dicarboxylic acids of 3 to 5 carbonatoms, a salt of the unsaturated acid, esters of the unsaturated acidderived from an alcohol having 1 to 8 carbon atoms, and mixturesthereof. Terpolymers of ethylene and these comonomers are also suitable.Ionomers, which are completely or partially neutralized copolymers ofethylene and the acids described above, are discussed in more detail inU.S. Pat. No. 3,264,272, already incorporated herein by reference. Inaddition, terpolymers of ethylene/vinyl acetate/carbon monoxide orethylene/methyl acrylate/carbon monoxide containing up to about 15percent by weight of carbon monoxide can also be employed.

Suitable ethylene/unsaturated carboxylic acid, salt and esterinterpolymers include ethylene/vinyl acetate (EVA) including, but notlimited to, the stabilized EVA described in U.S. Pat. No. 5,096,955,which is incorporated herein by reference; ethylene/acrylic acid (EAA)and its ionomers; ethylene/methacrylic acid and its ionomers;ethylene/methyl acrylate; ethylene/ethyl acrylate; ethylene/isobutylacrylate; ethylene/normal butyl acrylate; ethylene/isobutylacrylate/methacrylic acid and its ionomers; ethylene/normal butylacrylate/methacrylic acid and its ionomers; ethylene/isobutylacrylate/acrylic acid and its ionomers; ethylene/normal butylacrylate/acrylic add and its ionomers; ethylene/methyl methacrylate;ethylene/vinyl acetate/methacrylic acid and its ionomers; ethylene/vinylacetate/acrylic acid and its ionomers; ethylene/vinyl acetate/carbonmonoxide; ethylene/methacrylate/carbon monoxide; ethylene/normal butylacrylate/carbon monoxide; ethylene/isobutyl acrylate/carbon monoxide;ethylene/vinyl acetate/monoethyl maleate and ethylene/methylacrylate/monoethyl maleate. Particularly suitable copolymers are EVA;EAA; ethylene/methyl acrylate; ethylene/isobutyl acrylate; andethylene/methyl methacrylate copolyers and mixtures thereof. Certainproperties, such as tensile elongation, are taught to be improved bycertain combinations of these ethylene interpolymers described in U.S.Pat. No. 4,379,190, which is incorporated herein by reference. Theprocedures for making these ethylene interpolymers are well known in theart and many are commercially available.

Propylene based polymers are also suitable to make a film, sheet, orcoating according to this invention. Such propylene based polymers are,for example, homopolypropylene and propylene interpolymers, such ascopolymers of propylene with ethylene and/or a C₄-C₂₀ alpha-olefin,including impact copolymers and polypropylene random copolymers.

Further thermoplastic interpolymers suitable to practice the presentinvention are polyolefin interpolymers comprising

-   -   i) polymer units derived from at least one of ethylene and/or an        alpha-olefin monomer; and    -   ii) polymer units derived from one or more vinyl or vinylidene        aromatic monomers and/or one or more sterically hindered        aliphatic or cycloaliphatic vinyl or vinylidene monomers, or a        combination of at least one aromatic vinyl or vinylidene        monomer, and    -   iii) optionally polymer units derived from one or more        ethylenically unsaturated polymerizable monomer(s) other than        those derived from i) and ii).

Suitable α-olefins include, for example, α-olefins containing from 3 toabout 20, preferably from 3 to about 12, more preferably from 3 to about8 carbon atoms. These α-olefins do not contain an aromatic moiety.Particularly suitable are ethylene, propylene,butene-1,4-methyl-1-pentene, hexene-1 or octene-1 or ethylene incombination with one or more of propylene, butene-1,4-methyl-1 pentene,hexene-1 or octene-1.

Polymerizable ethylenically unsaturated monomer(s) include strained ringolefins such as norbornene and C₁-C₁₀ alkyl or C₆-C₁₀ aryl substitutednorbomenes, with an exemplary interpolymer beingethylene/styrene/norbornene.

Suitable vinyl or vinylidene aromatic monomers include, for example,those represented by the following formula:

wherein R¹ is selected from the group of radicals consisting of hydrogenand alkyl radicals containing from 1 to about 4 carbon atoms, preferablyhydrogen or methyl; each R² is independently selected from the group ofradicals consisting of hydrogen and alkyl radicals containing from 1 toabout 4 carbon atoms, preferably hydrogen or methyl; Ar is a phenylgroup or a phenyl group substituted with from 1 to 5 substituentsselected from the group consisting of halo, C₁-C₄-alkyl, andC₁-C₄-haloalkyl: and n has a value from zero to about 4, preferably fromzero to 2, most preferably zero. Exemplary vinyl aromatic monomersinclude styrene, vinyl toluene, x-methylstyrene, t-butyl styrene,chlorostyrene, including all isomers of these compounds, and the like.Particularly suitable such monomers include styrene and lower alkyl- orhalogen-substituted derivatives thereof. Preferred monomers includestyrene, α-methyl styrene, the lower alkyl-(C₁-C₄) or phenyl-ringsubstituted derivatives of styrene, such as for example, ortho-, meta-,and para-methylstyrene, the ring halogenated styrenes, para-vinyltoluene or mixtures thereof, and the like. The most preferred aromaticvinyl monomer is styrene.

By the term “sterically hindered aliphatic or cycloaliphatic vinyl orvinylidene compounds”, it is meant addition polymerizable vinyl orvinylidene monomers corresponding to the formula:

wherein A¹ is a sterically bulky, aliphatic or cycloaliphaticsubstituent of up to 20 carbons, R¹ is selected from the group ofradicals consisting of hydrogen and alkyl radicals containing from 1 toabout 4 carbon atoms, preferably hydrogen or methyl; each R² isindependently selected from the group of radicals consisting of hydrogenand alkyl radicals containing from 1 to about 4 carbon atoms, preferablyhydrogen or methyl; or alternatively R¹ and A¹ together form a ringsystem.

By the term “sterically bulky” it is meant that the monomer bearing thissubstituent is normally incapable of addition polymerization by standardZiegler-Natta polymerization catalysts at a rate comparable withethylene polymerizations.

Ethylene and alpha-olefins having a linear aliphatic structure such aspropylene, butene-1, hexene-1 and octene-1 are not considered to besterically hindered aliphatic monomers.

Preferred sterically hindered aliphatic or cycloaliphatic vinyl orvinylidene compounds are monomers in which one of the carbon atomsbearing ethylenic unsaturation is tertiarily or quatemarily substituted.Examples of such substituents include cyclic aliphatic groups such ascyclohexyl, cyclohexenyl, cyclooctenyl, or ring alkyl or arylsubstituted derivatives thereof, tert-butyl, norbornyl, and the like.Most preferred aliphatic or cycloaliphatic vinyl or vinylidene compoundsare the various isomeric vinyl-ring substituted derivatives ofcyclohexene and substituted cyclohexenes, and 5-ethylidene-2-norbornene.Especially suitable are 1-, 3-, and 4-vinylcyclohexene. Simple linearnon-branched α-olefins including for example, α-olefins containing from3 to about 20 carbon atoms such as propylene,butene-1,4-methyl-1-pentene, hexene-1 or octene-1 are not examples ofsterically hindered aliphatic or cycloaliphatic vinyl or vinylidenecompounds.

The interpolymers comprising polymer units defined above under i), ii)and iii) can be substantially random, pseudo-random, random,alternating, diadic, triadic, triadic or any combination thereof. Thatis, the interpolymer product can be variably incorporated and optionallyvariably sequenced. The preferred sequence is substantially random. Thepreferred substantially random interpolymers are the so-calledpseudo-random interpolymers as described in EP-A0 416 815 by James C.Stevens et al. and U.S. Pat. No. 5,703,187 by Francis J. Timmers, bothof which are incorporated herein by reference in their entirety.

The preferred polyolefin interpolymer are ethylene/styreneinterpolymers. Particularly preferred are substantially randomethylene/styrene interpolymers.

The term “variably incorporated” as used herein refers to aninterpolymer, particularly an ethylene/styrene interpolymer,manufactured using at least two catalyst systems wherein duringinterpolymerization the catalyst systems are operated at differentincorporation or reactivity rates. For example, the interpolymer producthaving a total styrene content of 36 weight percent is variablyincorporated where one catalyst system incorporates 22 weight percentstyrene and the other catalyst system incorporates 48 weight percentstyrene and the production split between the two catalyst systems is47/53 weight percentages.

Representative “pseudo-random” interpolymers are the ethylene/styreneinterpolymers described in U.S. Pat. No. 5,703,187, the disclosure ofwhich is incorporated herein in its entirety by reference.

“Random” interpolymers are those in which the monomer units areincorporated into the chain such that there exist various combinationsof ordering including blockiness, e.g. where either the ethylene or thealiphatic alpha-olefin monomer or the sterically hindered vinylidenemonomer or both can be repeated adjacent to one another.

Representative “alternating” interpolymers are, for example, alternatingethylene/styrene interpolymers in which the ethylene and the stericallyhindered vinylidene monomer occur in repeat alternate sequences on thepolymer chain in atactic or stereospecific structures (such as isotacticor syndiotactic) or in combinations of the general formula (AB)_(n).

The term “substantially random” as used herein in reference to theinterpolymers comprising the above-mentioned monomers i), ii) and iii),and to ethylene/styrene interpolymers in particular, generally meansthat the distribution of the monomers of the interpolymer can bedescribed by the Bernoulli statistical model or by a first or secondorder Markovian statistical model, as described by J. C. Randall inPolymer Sequence Determination. Carbon-13 NMR Method, Academic Press NewYork, 1977, pp. 71-78, the disclosure of which is incorporated herein byreference. Substantially random interpolymers do not contain more than15 mole percent of the total amount of vinyl or vinylidene aromaticmonomer in blocks of vinyl or vinylidene aromatic monomer of more than 3units.

Preferably, the substantially random interpolymer is not characterizedby a high degree (greater than 50 mole percent) of either isotacticityor syndiotacticity. This means that in the carbon-13 NMR spectrum of thesubstantially random interpolymer, the peak areas corresponding to themain chain methylene and methine carbons representing either meso diadsequences or racemic diad sequences should not exceed 75 percent of thetotal peak area of the main chain methylene and methine carbons.

A preferred method of preparation of the substantially randominterpolymers includes polymerizing a mixture of polymerizable monomersin the presence of one or more metallocene or constrained geometrycatalysts in combination with various cocatalysts, as described inEP-A-0,416,815 by James C. Stevens et al. and U.S. Pat. No. 5,703,187 byFrancis J. Timmers, both of which are incorporated herein by referencein their entirety. Preferred operating conditions for suchpolymerization reactions are pressures from atmospheric up to 3000atmospheres and temperatures from −30° C. to 200° C. Polymerizations andunreacted monomer removal at temperatures above the autopolymerizationtemperature of the respective monomers may result in formation of someamounts of homopolymer polymerization products resulting from freeradical polymerization.

Examples of suitable catalysts and methods for preparing thesubstantially random interpolymers are disclosed in EP-A-514,828); aswell as U.S. Pat. No.: 5,055,438; 5,057,475; 5,096,867; 5,064,802;5,132,380; 5,189,192; 5,321,106; 5,347,024; 5,350,723; 5,374,696;5,399,635; 5,470,993; 5,703,187; and 5,721,185, all of which patents andapplications are incorporated herein by reference.

The substantially random α-olefin/vinyl aromatic interpolymers can alsobe prepared by the methods described in JP 07/278,230 employingcompounds shown by the general formula

wherein Cp¹ and Cp² are cyclopentadienyl groups, indenyl groups,fluorenyl groups, or substituents of these, independently of each other;R¹ and R² are hydrogen atoms, halogen atoms, hydrocarbon groups withcarbon numbers of 1-12, alkoxyl groups, or aryloxyl groups,independently of each other; m is a group IV metal, preferably Zr or Hf,most preferably Zr; and R³ is an alkylene group or silanediyl group usedto cross-link Cp¹ and Cp².

The substantially random α-olefin/vinyl aromatic interpolymers can alsobe prepared by the methods described by John G. Bradfute et al. (W. R.Grace & Co.) in WO 95/32095; by R. B. Pannell (Exxon Chemical Patents,Inc.) in WO 94/00500; and in Plastics Technology, p. 25 (September1992), all of which are incorporated herein by reference in theirentirety.

Also suitable are the substantially random interpolymers which compriseat least one α-olefin/vinyl aromatic/vinyl aromatic/α-olefin tetraddisclosed in U.S. application Ser. No. 08/708,869 filed Sep. 4, 1996 andWO 98/09999 both by Francis J. Timmers et al. These interpolymerscontain additional signals in their carbon-13 NMR spectra withintensities greater than three times the peak to peak noise. Thesesignals appear in the chemical shift ranges of 43.70-44.25 ppm and38.0-38.5 ppm. Specifically, major peaks are observed at 44.1, 43.9, and38.2 ppm. A proton test NMR experiment indicates that the signals in thechemical shift region 43.70-44.25 ppm are methine carbons and thesignals in the region 38.0-38.5 ppm are methylene carbons.

It is believed that these new signals are due to sequences involving twohead-to-tail vinyl aromatic monomer insertions preceded and followed byat least one α-olefin insertion, e.g. anethylene/styrene/styrene/ethylene tetrad wherein the styrene monomerinsertions of said tetrads occur exclusively in a 1,2 (head to tail)manner. It is understood by one skilled in the art that for such tetradsinvolving a vinyl aromatic monomer other than styrene and an α-olefinother than ethylene that the ethylene/vinyl aromatic monomer/vinylaromatic monomer/ethylene tetrad will give rise to similar carbon-13 NMRpeaks but with slightly different chemical shifts.

These interpolymers can be prepared by conducting the polymerization attemperatures of from about −30° C. to about 250° C. in the presence ofsuch catalysts as those represented by the formula

wherein: each Cp is independently, each occurrence, a substitutedcyclopentadienyl group π-bound to M; E is carbon or Si; M is a group IVmetal, preferably Zr or Hf, most preferably Zr: each R is independently,each occurrence, hydrogen, hydrocarbyl, silahydrocarbyl, orhydrocarbylsilyl, containing up to about 30 preferably from 1 to about20 more preferably from 1 to about 10 carbon or silicon atoms; each R¹is independently, each occurrence, hydrogen, halo, hydrocarbyl,hyrocarbyloxy, silahydrocarbyl, hydrocarbylsilyl containing up to about30, preferably from 1 to about 20, more preferably from 1 to about 10carbon or silicon atoms or two R¹ groups together can be a C₁-C₁₀hydrocarbyl substituted 1,3-butadiene; M is 1 or 2; and optionally, butpreferably in the presence of an activating cocatalyst. Particularly,suitable substituted cyclopentadienyl groups include those illustratedby the formula:

-   -   wherein each R is independently, each occurrence, hydrogen,        hydrocarbyl, silahydrocarbyl, or hydrocarbylsilyl, containing up        to about 30, preferably from 1 to about 20, more preferably from        1 to about 10 carbon or silicon atoms or two r groups together        form a divalent derivative of such group. Preferably, R        independently each occurrence is (including where appropriate        all isomers) hydrogen, methyl, ethyl, propyl, butyl, pentyl,        hexyl, benzyl, phenyl or silyl or (where appropriate) two such R        groups are linked together forming a fused ring system such as        indenyl, fluorenyl, tetrahydroindenyl, tetrahydrofluorenyl, or        octahydrofluorenyl.

Particularly preferred catalysts include, for example,racemic-(dimethylsilanediyl)-bis-(2-methyl-4-phenylindenyl) zirconiumdichloride, racemic-(dimethylsilanediyl)-bis-(2-methyl-4-phenylindenyl)zirconium 1,4-diphenyl-1,3-butadiene,racemic-(dimethylsilanediyl)is-(2-methyl-4-phenylindenyl) zirconiumdi-C₁₋₄, alkylracemic-(dimethylsilanediyl)-bis-(2-methyl-4-phenylindenyl) zirconiumdi-C₁-C₄ alkoxide, or any combination thereof and the like.

It is also possible to use the following titanium-based constrainedgeometry catalysts,[N-(1,1-dimethylethyl)-1,1-dimethyl-1-[(1,2,3,4,5-η)-1,5,6,7-tetrahydro-s-indacen-1-yl]silanaminato(2-)-N]titaniumdimethyl; (1-indenyl)(tert-butylamido)dimethyl-silane titanium dimethyl;((3-tert-butyl)(1,2,3,4,5-η)-1-indenyl)(tert-butylamido) dimethylsilanetitanium dimethyl; and((3-iso-propyl)(1,2,3,4,5-η)-1-indenyl)(tert-butyl amido)dimethylsilanetitanium dimethyl, or any combination thereof and the like.

Further preparative methods for the interpolymers used in the presentinvention have been described in the literature. Longo and Grassi(Makromol. Chem., Volume 191, pages 2387 to 2396 [1990]) and D'Annielloet al. (Journal of Applied Polymer Science, Volume 58, pages 1701-1706[1995]) reported the use of a catalytic system based on methylalumoxane(MAO) and cyclopentadienyltitanium trichloride (CpTiCl₃) to prepare anethylene-styrene copolymer. Xu and Lin (Polymer Preprints, Am. Chem.Soc., Div. Polym. Chem., Vol. 35, pages 686-687 [1994]) have reportedcopolymerization using a MgCl₂/TiCl₄/NdCl₃/Al(iBu)₃ catalyst to giverandom copolymers of styrene and propylene. Lu et al. (Journal ofApplied Polymer Science, Vol. 53, pp. 1453 to 1460, 1994) have describedthe copolymerization of ethylene and styrene using aTiCI₄/NdCl₃/MgCl₂/Al(Et)₃ catalyst. Semetz and Mulhaupt, (Macromol.Chem. Phys., Vol. 197, pp. 1071-1083, 1997) have described the influenceof polymerization conditions on the copolymerization of styrene withethylene using Me₂Si(Me₄ Cp)(n-tert-butyl)TiCl₂/methylaluminoxaneZiegler-Natta catalysts. Copolymers of ethylene and styrene produced bybridged metallocene catalysts have been described by Arai, Toshiaki andSuzuki (Polymer Preprints, Am. Chem. Soc., Div. Polym. Chem., Volume 38,pages 349-350, 1997; U.S. Pat. No. 5,883,213 and DE-A-197 11 339) and inU.S. Pat. No. 5,652,315, issued to Mitsui Toatsu Chemicals, Inc. Themanufacture of α-olefin/vinyl aromatic monomer interpolymers such aspropylene/styrene and butene/styrene is as described in U.S. Pat. No.5,244,996, issued to Mitsui Petrochemical Industries Ltd. or U.S. Pat.No. 5,652,315 also issued to Mitsui Petrochemical Industries Ltd, or asdisclosed in DE-A-1 97 11 339 to Denki Kagaku Kogyo KK. All the abovemethods disclosed for preparing the interpolymer component areincorporated herein by reference. Also, although of high isotacticityand therefore not “substantially random”, the random copolymers ofethylene and styrene as disclosed in Polymer Preprints Vol. 39, No. 1,March 1998 by Toru Aria et al. can also be employed for the purposes ofthe present invention.

While preparing the substantially random interpolymer, an amount ofatactic vinyl aromatic homopolymer may be formed due tohomopolymerization of the vinyl aromatic monomer at elevatedtemperatures. The presence of vinyl aromatic homopolymer is in generalnot detrimental for the purposes of the present invention and can betolerated.

The substantially random interpolymer usually contains from about 5 toabout 65, preferably from about 5 to about 55, more preferably fromabout 10 to about 50 mole percent of at least one vinyl or vinylidenearomatic monomer; or sterically hindered aliphatic or cycloaliphaticvinyl or vinylidene monomer; or both; and from about 35 to about 95,preferably from about 45 to about 95, more preferably from about 50 toabout 90 mole percent of ethylene and/or at least one aliphatic α-olefinhaving from about 3 to about 20 carbon atoms.

The most preferred substantially random interpolymers are interpolymersof ethylene and styrene and interpolymers of ethylene, styrene and atleast one alpha-olefin containing from 3 to 8 carbon atoms.

The presence of other polymerizable ethylenically unsaturated monomer(s)is optional.

The density of the substantially random interpolymer is generally about0.930 g/cm³ or more, preferably from about 0.930 to about 1.045 g/cm³,more preferably from about 0.930 to about 1.040 g/cm³, most preferablyfrom about 0.930 to about 1.030 g/cm³. The molecular weightdistribution, M_(w)/M_(n) is generally from about 1.5 to about 20,preferably from about 1.8 to about 10, more preferably from about 2 toabout 5.

Thermoplastic polymers useful in the present invention also includealkenyl aromatic polymers. The alkenyl aromatic polymers may becomprised solely of one or more alkenyl aromatic homopolymers, one ormore alkenyl aromatic copolymers, a blend of one or more of each ofalkenyl aromatic homopolymers and copolymers, or blends of any of theforegoing with a non-alkenyl aromatic polymer. Regardless ofcomposition, the alkenyl aromatic polymer material comprises greaterthan 50 weight percent and preferably greater than 70 weight percentalkenyl aromatic monomeric units. Most preferably, the alkenyl aromaticpolymer material is comprised entirely of alkenyl aromatic monomericunits.

Suitable alkenyl aromatic polymers include homopolymers and copolymersderived from alkenyl aromatic compounds such as styrene,alpha-methylstyrene, ethylstyrene, vinyl benzene, vinyl toluene,chlorostyrene, and bromostyrene, t-butyl styrene, including all isomersof these compounds. Suitable polymers also include alkenyl aromaticpolymers having a high degree of syndiotactic configuration. A preferredalkenyl aromatic polymer is polystyrene. Minor amounts ofmonoethylenically unsaturated compounds such as C₂-C₆ alkyl acids andesters, ionomeric derivatives, and C₄-C₆ dienes may be copolymerizedwith alkenyl aromatic compounds. Examples of copolymerizable compoundsinclude acrylic acid, methacrylic acid, ethacrylic acid, maleic acid,itaconic acid, acrylonitrile, maleic anhydride, methyl acrylate, ethylacrylate, isobutyl acrylate, n-butyl acrylate, methyl methacrylate,vinyl acetate and butadiene.

General purpose polystyrene is the most preferred alkenyl aromaticpolymer material. The term “general purpose polystyrene” is defined inthe Encyclopedia of Polymer Science and Engineering, Vol. 16, pp. 62-71,1989. Such polystyrene is often called also referred to as crystalpolystyrene or polystyrene homopolymer.

The monoalkenyl aromatic polymers may be suitably modified by rubbers toimprove their impact properties. Examples of suitable rubbers arehomopolymers of C₄-C₆ conjugated dienes, especially butadiene orisoprene; interpolymers of one or more alkenyl aromatic monomers, andone or more C₄-C₆ conjugated dienes, interpolymers of ethylene andpropylene or ethylene, propylene and a nonconjugated diene, especially1,6-hexadiene or ethylidene norbornene; homopolymers of C₄-C₆ alkylacrylates; interpolymers of C₄-C₆ alkyl acrylates and aninterpolymerizable comonomer, especially an alkenyl aromatic monomer ora C₁-C₄ alkyl methacrylate. Also included are graft polymers of theforegoing rubbery polymers wherein the graft polymer is an alkenylaromatic polymer. A preferred alkenyl aromatic polymer for use in all ofthe foregoing rubbery polymers is styrene. A most preferred rubberypolymer is polybutadiene or a styrene/butadiene copolymer.

Impact modified alkenyl aromatic polymers are well known in the art andcommercially available.

Suitable polymers to be employed as Component (A) also include alkenylaromatic polymers having a high degree of syndiotactic configuration.

Preferred alkenyl aromatic polymers include polystyrene, syndiotacticpolystyrene, rubber-modified high impact polystyrene, poly(vinyl-toluene), and poly(alpha-methylstyrene).

Thermoplastic polymers for use in the present invention also includemelt-stable lactide polymers or poly(lactide). By “melt-stable” it ismeant that the lactide polymer when subjected to melt-processingtechniques adequately maintains its physical properties and does notgenerate byproducts in sufficient quantity to foul or coat processingequipment. Lactide polymers are obtainable from lactic acid and maytherefore also be referred to as PLA resins. Such lactide polymers aredisclosed, for example, in U.S. Pat. No. 5,773,562, the disclosure ofwhich is incorporated herein by reference in its entirety. Suitable PLAresins are supplied commercially by Cargill Dow under the designationEcoPLA. Poly(lactide) offers the benefits of being a renewable resourcematerial which may be obtained from corn and of being biodegradable(compostable). Thus, poly(lactide) may be disposed of in anenvironmentally sound fashion.

The poly(lactide) formulation may include a plasticizer. Suitableplasticizers and selection criteria are disclosed in U.S. Pat. No.5,773,562 (column 14, line 35-column 15, line 28).

To improve certain properties of poly(lactide) it may be advantageous toblend a second polymer with the poly(lactide). Suitable ‘secondpolymers’ and selection criteria are disclosed in U.S. Pat. No.5,773,562 (column 7, lines 21-47).

Suitable elastomers and block polymers include, for example, blockcopolymers such as styrene/butadiene (SB) block copolymers,styrene/ethylene-butene/styrene (SEBS) block polymers,styrene/ethylene-propylene/styrene (SEPS) block polymers,styrene/isoprene/styrene (SIS) block polymers, andstyrene/butadiene/styrene (SBS) block polymers; polyester/polyetherblock polymers (e.g., HYTEL™); ethylene/propylene rubbers; andethylene/propylene/diene (EPDM) elastomers. Preferred elastomers arevinyl aromatic/conjugated diene block polymers (e.g. SBS) that have beensubstantially hydrogenated; that is the block copolymer is characterizedby each hydrogenated vinyl aromatic polymer block having a hydrogenationlevel of greater than 90 percent and each hydrogenated conjugated dienepolymer block having a hydrogenation level of greater than 95 percentwhere hydrogenation converts unsaturated moieties into saturatedmoieties. Also, preferred block polymers have a higher ratio of rigidpolymer blocks (e.g. vinyl aromatic polymer blocks) to rubber polymerblocks (e.g. conjugated diene polymer blocks).

Suitable thermoplastic phenoxy resins include polyhydroxyaminoether,polyhydroxyesterether or polyhydroxyether.

The polymers used in the present invention may be modified, for example,but not limited to, by typical grafting, hydrogenation, functionalizing,or other reactions well known to those skilled in the art.

The graft modification of polymers, particularly polyolefins, such aspolyethylenes and polypropylenes, with various unsaturated mononomers iswell known in the art. Such a modification renders an essentiallynonpolar material compatible, at least to some limited extent, with apolar material. Graft modification of the polymers is advantageouslyaccomplished by employing an organic compound containing at least oneethylenic unsaturation (e.g., at least one double bond), and at leastone carbonyl group (−C═O). Representative of compounds that contain atleast one carbonyl group are the carboxylic acids, anhydrides, estersand their salts, both metallic and nonmetallic. Preferably, the organiccompound contains ethylenic unsaturation cponjugated with a carbonylgroup. Representative compounds include maleic, fumaric, acrylic,methacrylic, itatonic, crotonic, methyl crotonic and cinnamic acid andtheir anhydride, ester and salt derivatives, if any. Maleic anhydride isthe preferred unsaturated organic compound containing at least oneethylenic unsaturation and at least one carbonyl group.

The unsaturated organic compound content of the grafted polymer is atleast about 0.01 weight percent, and preferably at least about 0.05weight percent, based on the combined weight of the polymer and theorganic compound. The maximum amount of unsaturated organic compoundcontent can vary to convenience, but typically it does not exceed about10 weight percent, preferably it does not exceed about 5 weight percent,and more preferably it does not exceed about 2 weight percent. Theunsaturated organic compound can be grafted to the polymer by any knowntechnique. The graft-modified polymer may be blended with one or moreother polymers, either grafted or ungrafted. For example, a graftmodified ethylene-based or propylene-based polymer may be blended withone or more other polyolefins, either grafted or ungrafted, or with oneor more polymers other than a polyolefin, either grafted or ungrafted.

The polymers may be sulfonated or chlorinated to provide functionalizedderivatives according to established techniques. In addition oralternatively, the polymers may be modified by suitable chain-extendingor cross-linking processes using e.g. a physical or a chemical method,including, but not limited to, peroxide-, silane-, sulfur-, radiation-,or azide-based cure systems. A more detailed description of the variouscross-linking technologies is described in U.S. Pat. No. 5,869,591 andEP-A-778,852, the entire contents of both of which are hereinincorporated by reference. Dual cure systems, which use a combination ofheat, moisture cure and radiation steps, may be effectively employed.Dual cure systems are disclosed, for example, in EP-A-0 852 596,incorporated herein by reference. For instance, it may be desirable toemploy peroxide crosslinking agents in conjunction with radiation, andsulfur-containing crosslinking agents in conjunction with silanecrosslinking agents.

The present invention also provides a film, sheet, or coating, whereinthe film, sheet, or coating, the thermoplastic polymeric material orboth have been cured, irradiated, or crosslinked. Preferably, the cured,irradiated or crosslinked thermoplastic polymer is a polyolefin, morepreferably a polyolefin as defined above, and most preferably anethylene-based polymer. As used herein, “crosslinking” and “crosslinked”include partially crosslinking (crosslinked) as well as fullycrosslinking (crosslinked), as long as the crosslinking results in a gelwhich is verifiable via ASTM D2765, Procedure A. The variouscross-linking agents can be used alone, or in combination with oneanother.

Suitable heat-activated cross-linking agents include free radicalinitiators, preferably organic peroxides, more preferably those with onehour half lives at temperatures greater than 120° C. For example,suitable cross-linking agents are organic peroxides, such as1,1-di-t-butyl peroxy-3,3,5-trimethylcyclohexane, dicumyl peroxide,2,5-dimethyl-2,5-di(t-butyl peroxy) hexane, t-butyl-cumyl peroxide, α,α′-di(butyl peroxy)-diisopropyl benzene,di-t-butyl peroxide, and2,5-dimethyl-2,5-di-(t-butyl peroxy) hexyne. Dicumyl peroxide is thepreferred agent. Additional teachings to organic peroxide cross-linkingagents are seen in C. P. Park, Supra, pp. 198-204, which is Incorporatedherein by reference.

Alternatively, polymers may be crosslinked or cured by first grafting asilane onto the polymer backbone and thereafter subjecting or exposingthe silane grafted polymer to water or atmospheric moisture. Preferably,the silane grafted polymer is subjected to or exposed to water oratmospheric moisture after a shaping or fabrication operation.

Suitable silanes for silane crosslinking of the polymer, e.g. theethylene polymer, include those of the general formula

in which R¹ is a hydrogen atom or methyl group; x and y are 0 or 1 withthe proviso that when x is 1, y is 1; n is an integer from 1 to 12inclusive, preferably 1 to 4, and each R independently is a hydrolyzableorganic group such as an alkoxy group having from 1 to 12 carbon atoms(e.g. methoxy, ethoxy, butoxy), aryloxy group (e.g. phenoxy), araloxygroup (e.g. benzyloxy), aliphatic acyloxy group having from 1 to 12carbon atoms (e.g. formyloxy, acetyloxy, propanoyloxy), amino orsubstituted amino groups (alkylamino, arylamino), or a lower alkyl grouphaving 1 to 6 carbon atoms inclusive, with the proviso that not morethan one of the three R groups is an alkyl.

Suitable silanes may be grafted to a suitable (ethylene) polymer by theuse of a suitable quantity of organic peroxide, either before or duringa shaping or fabrication operation. However, preferably, the silane isgrafted onto the polymer before shaping or fabrication operations. Inany case, the curing or crosslinking reaction takes place following theshaping or fabrication operation by reaction between the grafted silanegroups and water. The water permeating into the bulk polymer from theatmosphere or from a water bath or “sauna”. The phase of the processduring which the crosslinks are created is commonly referred to as the“cure phase” and the process itself is commonly referred to as “curing”.

Any silane that will effectively graft to and crosslink the polymer canbe used in the present invention. Suitable silanes include unsaturatedsilanes that comprise an ethylenically unsaturated hydrocarbyl group,such as a vinyl, allyl, isopropenyl, butenyl, cyclohexenyl orγ-(meth)acryloxy allyl group, and a hydrolyzable group, such as, forexample, a hydrocarbyloxy, hydrocarbonyloxy, or hydrocarbylamino group.Examples of hydrolyzable groups include methoxy, ethoxy, formyloxy,acetoxy, proprionyloxy, and alkyl or arylamino groups. Preferred silanesare the unsaturated alkoxy silanes which can be grafted onto thepolymer. These silanes and their method of preparation are more fullydescribed in U.S. Pat. No. 5,266,627 to Meverden, et al. Vinyltrimethoxy silane, vinyl triethoxy silane, γ-(meth)acryloxy propyltrimethoxy silane and mixtures of these silanes are the preferred silanecrosslinkers for use in this invention. It a filler is present, thenpreferably the crosslinker includes vinyl triethoxy silane.

The amount of silane crosslinker used in the present invention can varywidely depending several factors such as the silane itself, processingconditions, grafting efficiency, organic peroxide selection, theultimate application, and similar factors.

However, typically at least 0.5, preferably at least 0.7, parts perhundred resin (phr) is used. Considerations of convenience and economyare usually the two principal limitations on the maximum amount ofsilane crosslinker used, and typically the maximum amount of silanecrosslinker does not exceed 5, preferably it does not exceed 2, phr.

The silane crosslinker is grafted to the polymer by any conventionalmethod, typically in the presence of a free radical initiator e.g.peroxides and azo compounds, or by ionizing radiation, etc. A suitablegrafting method is disclosed in WO 95/29197, the disclosure of which isincorporated herein by reference.

But, for efficient silane grafting, organic initiators are preferred,such as an azo compound or any one of the peroxide initiators, forexample, dicumyl peroxide, di-tert-butyl peroxide, t-butyl perbenzoate,benzoyl peroxide, cumene hydroperoxide, t-butyl peroctoate, methyl ethylketone peroxide, 2,5-dimethyl-2,5-di-(t-butyl peroxy)hexane, laurylperoxide, and tert-butyl peracetate. A suitable azo compound isazobisisobutyl nitrite. The amount of initiator can vary, but it istypically present in an amount of at least 0.04, preferably at least0.06, phr. Typically, the initiator does not exceed 0.15, preferably itdoes not exceed about 0.10, phr. The ratio of silane crosslinker toinitiator also can vary widely, but the typical crosslinker to initiatorratio is between 10 to 1 to 30 to 1, preferably between 18 to 1 and 24to 1.

While any conventional method can be used to graft the silanecrosslinker to the polymer, one preferred method is blending the twowith the initiator in the first stage of a reactor extruder, such as aBuss kneader. The grafting conditions can vary, but the melttemperatures are typically between 160° C. and 260° C., preferablybetween 190° C. and 230° C., depending upon the residence time and thehalf life of the initiator.

Also suitable for the purpose of the present invention are moisture curesilane copolymers, such as ethylene-vinyl silane copolymers and ethylenevinyl acetate-vinyl silane polymers.

Crosslinking by irradiation may be accomplished by the use of highenergy, ionizing electrons (electron beam), ultra violet rays, X-rays,gamma rays, beta particles, controlled thermal heating, or anycombination thereof. Electron beam irradiation is preferred.Advantageously, electrons are employed up to 70 megarads dosages. Theirradiation source can be any apparati known in the art such as anelectron beam generator operating in a range of about 50 kilovolts toabout 12 megavolts with a power output capable of supplying the desireddosage. The voltage of the electron beam generator can be adjusted toappropriate levels which may be, for example, 100,000, 300,000,1,000,000 or 2,000,000 or 3,000,000 or 6,000,000 or higher or lower. Inelectron beam irradiation, the irradiation is usually carried out at adosage between about 1 megarads to about 150 megarads, preferablybetween about 3 to about 50 megarads. Further, electron beam irradiationcan be carried out conveniently at room temperature, although higher andlower temperatures, for example 0° C. to about 60° C., may also beemployed. Furthermore, electron beam irradiation can be carried out inair atmosphere, or in reduced oxygen atmosphere or in inert gasatmosphere. Preferably, electron beam irradiation is carried out aftershaping or fabrication of the article.

Also, in a preferred embodiment, a polyolefin is incorporated with apro-rad additive and is subsequently irradiated with electron beamirradiation at about 8 to about 20 megarads. Suitable pro-rad additivesare compounds which are not activated during normal fabrication orprocessing of the polymer, but are activated by the application oftemperatures (heat) substantial above normal fabrication or processingtemperatures or ionizing energy (or both) to effectuate some measurablegelation or preferably, substantial crosslinking.

Representative pro-rad additives include, but are not limited to, azocompounds, organic peroxides and polyfunctional vinyl or allyl compoundssuch as, for example, triallyl cyanurate, triallyl isocyanurate,pentaerthritol tetramethacrylate, glutaraldehyde, ethylene glycoldimethacrylate, dially maleate, dipropargyl maleate, dipropargylmonoallyl cyanurate, dicumyl peroxide, di-tert-butyl peroxide, t-butylperbenzoate, benzoyl peroxide, cumene hydroperoxide, t-butyl peroctoate,methyl ethyl ketone peroxide, 2,5-dimethyl-2,5-di(t-butyl peroxy)hexane,lauryl peroxide, tert-butyl peracetate, azobisisobutyl nitrite and thelike and combination thereof. Preferred pro-rad additives for use in thepresent invention are compounds which have poly-functional (i.e. atleast two) moieties such as C═C, C═N or C═O.

At least one pro-rad additive can be introduced to the polymer by anymethod known in the art. But, preferably the pro-rad additive(s) isintroduced via a masterbatch concentrate comprising the same ordifferent base resin as the polymer. Preferably, the pro-rad additiveconcentration for the masterbatch is relatively high e.g., about 25weight percent (based on the total weight of the concentrate).

Pro-rad additives are introduced to the polyolefin in any effectiveamount. Preferably, the at least one pro-rad additive introductionamount is from about 0.001 to about 5 weight percent, more preferablyfrom about 0.005 to about 2.5 weight percent and most preferably fromabout 0.015 to about 1 weight percent based on the total weight of thepolymer. Crosslinking can also be promoted with a crosslinking catalyst,and any catalyst that will provide this function can be used. Suitablecatalysts generally include organic bases, carboxylic acids, andorganometallic compounds including organic titanates and complexes orcarboxylates of lead, cobalt, iron, nickel, zinc and tin.Dibutyltindilaurate, dioctyltinmaleate, dibutyltindiacetate,dibutyltindioctoate, stannous acetate, stannous octoate, leadnaphthenate, zinc caprylate, cobalt naphthenate; and the like. Tincarboxylate, especially dibutyltindilaurate and dioctyltinmaleate, areparticularly effective for this invention. The catalyst (or mixture ofcatalysts) is present in a catalytic amount, typically between about0.015 and about 0.035 phr.

The film, sheet, or coating of the invention may also comprise suitablemixtures, such as blends, of thermoplastic polymers. Polymer mixtures orcompositions can be formed by any convenient method. If desired orrequired, compatibilization between two immiscible or incompatiblepolymers can be effected by a suitable compatibilizer. Preparing thecompositions by physical admixture includes dry blending, melt blendingand solution blending, that is dissolving one or both of the componentsin a suitable solvent, such as for example a hydrocarbon, and combiningthe components followed by removing the solvent or solvents. Dryblending involves blending the individual components in solidparticulate and subsequently melt mixing in a mixer or by mixing thecomponents together directly in a mixer (for example, a Banbury mixer, aHaake mixer, a Brabender internal mixer, or a single or twin screwextruder including a compounding extruder and a side-arm extruderemployed directly downstream of a interpolymerization process.

The mixtures can further be formed in-situ. For example, blendscomprising a substantially linear ethylene interpolymer may be formedvia interpolymerization of ethylene and the desired α-olefin using aconstrained geometry catalyst in at least one reactor and a constrainedgeometry catalyst or a Ziegler-type catalyst in at least one otherreactor. The reactors can be operated sequentially or in parallel. Anexemplary in-situ interpolymerization process is disclosed inInternational Application WO 94/01052, incorporated herein by reference.The blends may be prepared using two reactors operated in series or inparallel, or by in-reactor blending using two or more catalysts in asingle reactor or combinations of multiple catalysts and multiplereactors. The general principle of making polymer blends by in-reactorblending using two or more catalysts in a single reactor or combinationsof multiple catalysts and multiple reactors is described in WO 93/13143,EP-A-0 619 827, and U.S. Pat. No. 3,914,362, each of which areincorporated herein by reference. The present polyolefin compositionscan be prepared by selecting appropriate catalyst and process conditionswith a view to the final composition characteristics.

Thermoplastic polymers suitable for use in the present invention alsoinclude recycled and scrap materials and diluent polymers (bothencompassed by the expression “diluent materials”), to the extent thatthe desired performance properties are maintained. Exemplary diluentmaterials include, for example, elastomers, rubbers and anhydridemodified polyethylenes (for example, polybutylene and maleic anhydridegrafted LLDPE and HDPE) as well as high pressure polyethylenes such as,for example, low density polyethylene (LDPE), EAA interpolymers,ethylene/vinyl acetate (EVA) interpolymers and ethylene/methacrylate(EMA) interpolymers, and combinations thereof. In some instances, it ispreferable for a polymer mixture to contain less than 50 weight percent,more preferably less than 30 weight percent diluent material,particularly when the diluent material is a styrene copolymer, astyrene/butadiene rubber or a styrene/butadiene/styrene block copolymer(SBS).

Additives

Optionally, the film, sheet, or coating of the present invention mayfurther comprise additives, including, but not limited to, antioxidants(e.g., hindered phenolics, such as IRGANOX™ 1010 or IRGANOX™ 1076supplied by Ciba Specialty Chemicals), phosphites (e.g., IRGAFOS™ 168also supplied by Ciba Specialty Chemicals), cling additives (e.g.,polyisobutylene (PIB), SANDOSTAB PEPQ™ (supplied e.g. by Ciba SpecialtyChemicals), pigments, colorants, deodorants, fillers, plasticizers,medical ornaments such as diaper rash ornaments, UV stabilizers, heatstabilizers, processing aid and combinations thereof.

Although generally not required, the film, sheet, or coating of thepresent invention may also contain additives to enhance antiblocking(antiblock agents) coefficient of friction characteristics (slip agents)including, but not limited to, untreated and treated silicon dioxide,talc, calcium carbonate, and clay, as well as primary, secondary andsubstituted fatty acid amides, and combinations thereof.

Still other additives, such as quaternary ammonium compounds alone or incombination with ethylene-acrylic acid (EAA) copolymers or otherfunctional polymers, may also be added to enhance the anti-staticcharacteristics of the film, sheet, or coating of the invention.Enhanced anti-static characteristics promote the usefulness of theinventive film, sheet, or coating in, for example, cushioned packagingof electronically sensitive goods.

Films, Sheets, Coatings

The films, sheeting, or coatings of the present invention arecharacterized in that they comprise at least one layer, which has a‘fringed’ surface microstructure. In this document, a film, sheet, orcoating, or a layer thereof having such fringed surface microstructureis also referred to as “fringed film, sheet, coating or layer”,including each item individually, e.g. “fringed film”. The fringedsurface microstructure may cover a desired part or parts, orsubstantially the entire fringed item, depending on the intended use ofsaid item. When magnified, the side view of a fringed surfacemicrostructure shows a broken up base consisting of a pattern of peaksor protrusions separated by troughs or valleys. In top orcross-sectional view, the peaks have a crown-like or crater-likeappearance and are at least partially hollow at the top, meaning that atleast about 25 percent of the volume at the top of the peak are empty orunfilled. “At least partially hollow” includes completely hollow peaks.Such at least partially hollow peaks or so-called craters are referredto as ‘fringes’. The base (of the fringe layer) and the fringes(themselves) are composed of the same thermoplastic polymeric material.The fringes are integral components of the layer forming the fringedsurface microstructure. The peaks are generally non-perforated, meaningthat the base at the bottom of the craters is generally not perforated.

The fringes may have various three-dimensional structures. For example,they may approximate tubular or conical shapes. Various parameters canbe used to characterize the geometry of the fringes, such as therelation between different diameters. For example, the diameter at thebottom of the fringe may be larger, about the same, or smaller than thediameter at the tip of the fringe. Exemplary three-dimensional fringestructures mimic bottle-like or wine glass-like shapes. The side wallsof the fringe typically become thinner towards the top of the crater.The brim at the top of the peak or crater may be (relatively) smooth,wave-like or fuzzy. The opening may be round or elliptical.

If the fringed microstructure of the film, sheet, or coating is notdiscernible with the naked eye, it is microscopically discernible, forexample at an enlargement of about 10 times or more. For example; whenappropriately magnified using Scanning Electron Microscopy (SEM), thetop view of the fringed surface microstructure exhibits a pattern ofcraters, for example a pattern of tubes or cylinders, which emerge fromthe base. The cross-sectional view, cutting through the center of thecraters, exhibits peaks for the walls of the craters, followed byvalleys which represent the crater holes as well as the surface of thebase which is between the craters as dictated by the pattern of thebase.

The fringed surface microstructure can be characterized by one or morequantitative parameters relating to the dimensions of the (overall)fringe, its (inner) hollow part, or both. Suitable parameters includefringe density, length or height (ratios), diameters, hollowness indexor enhanced surface area, taken alone or in any combination. The fringedfilm, sheet or coating of the invention may be designed to comprisesubstantially similar or different fringe structures.

Methods to determine the dimensional fringe parameters are known in theart, such as microscopy or optical surface profilometry.

In brief, suitable samples, such as cross-sections, of a fringed film,sheet, or coating may be analyzed by optical or electron microscopyusing microtoming. Several cross-sections, for example 20 to 40, shouldbe obtained such that the hollow center of a crater can be identified.For example, cross-sections from items with relatively short fringes,e.g. with lengths below about 75 microns, are advantageously cut usingan ultra-sharp, durable tool, such as a diamond knife, at very lowtemperatures, e.g. at −120° C. (minus 120 degrees Celsius).Cross-sections of items with longer fringes are embedded in a mediumsuitable for embedding tissue, such as Paraplast™ wax.

Optical surface profilometry is a method capable of profiling a roughsurface having height variations. The method is performed with anon-contact optical profiler using vertical scanning interferometry(VSI) technology. Such profilers are commercially available, e.g. fromADE Phase Shift, or VEECO Methology Group, both in Tucson, Ariz., USA.Details on the method and the device are disclosed in an article by P.J. Caber et al., “New interferometric Profiler for Smooth and RoughSurfaces”, Proc. SPIE, page 2088, October 1993, and U.S. Pat. No.5,133,601; 5,204,734 or 5,355,211, all by D. K. Cohen and C .P. Brophyand incorporated herein by reference. Vertical scanning interferometryis characterized in that the interferometric objective moves verticallyto scan the surface at varying heights. The source light beam is splitwithin the interferometer. The beams reflected from the test surface andthe reference surface recombine to form interference fringes. Theseinterference fringes are the alternating light and dark bands whichappear when the surface is in focus. The contrast of these interferencefringes(or modulation) increases as the sample is translated into focus,then falls as it is translated past focus. As the system scans downward,an interference signal for each point on the surface is recorded. Theinterference fringe signal is then processed (demodulated) using aseries of digital processing algorithms to calculate surface heights.From these heights and corresponding positions, a three-dimensionalprofile height function as well as two-dimensional cross-sectional viewscan be generated. The dimensional parameters used for fringecharacterization are derivable from these structural data.

For the purpose of this invention, optical, non-contact profilometry isused to characterize the fringe structure and determine the dimensionalparameters. This method has the advantage of being a non-destructivemethod, which does not require time-consuming sample preparation. Therange of the surface height that can be profiled using this techniquewas 0.1 nm to 1 mm standard with less than 1% error. The method providestwo-dimensional as well as three-dimensional structural data enablingthe determination of several parameters with one measurement. The methodutilizes a white light source. If a fringed surface microstructure iscomposed of fringes with a structure which is unsuitable to be measuredby profilometry, the dimensional parameters are measured via opticalmicroscopy.

The optical profilometry measurement can generate directly a number ofsurface microstructure data, such as the surface area ratio, thearithmetic average roughness, the average maximum peak-to-valley valueand the average spacing of roughness peaks. The surface area is thetotal of the exposed three-dimensional surface area being analyzed,including peaks and valleys. The lateral surface area is the surfacearea measured in the lateral direction. The surface area ratio iscalculated as the ratio of the surface area divided by the lateralsurface area. The arithmetic average roughness, designated as Ra insurface metrology, is the arithmetic mean height relative to thereference mean plane. The reference mean plane is the three-dimensionalreference surface to which all points in the dataset are related. The Ravalue is calculated as:${Ra} = {\frac{1}{MN}{\sum\limits_{j = 1}^{M}\quad{\sum\limits_{i = 1}^{N}\quad{Z_{ji}}}}}$

For the purpose of the present invention, the Ra values relate to thetotal volume of fringes when the base of the film is selected as thereference mean plane.

The average maximum peak-to-valley value is the average maximumpeak-to-valley height over the evaluation area, which is calculated asthe average of each maximum peak-to-valley height of the measured dataarray. The average maximum peak-to-valley height Rz, is calculated as${{Rz} = {\frac{1}{N}{\sum\limits_{i = 1}^{N}\quad\left( {{Hi} - {Li}} \right)}}},$wherein Hi are the highest points and Li are the lowest points found inthe data array, and N is the number of data arrays within the dataset(evaluation area). The peak-to-valley value is the height differencebetween adjacent peaks and valleys. For the purpose of the presentinvention, the average maximum peak-to-valley height corresponds to thefringe length or height (H).

The density of individual fringes is at least about 1000 per squarecentimeter (cm²), preferably at least about 2000/cm². Preferably, thedensity is less than 10,000 per square centimeter. Most preferably, thedensity is In the range of from about 2000 to about 5000 fringes percm². If desired, the fringe density may be selected to vary within thefringed surface microstructure.

Fringe density can be determined by optical or electron microscopy, andsurface profilometry.

FIG. 1 shows a cross-sectional view of an exemplary tubular fringe (2)which is integral with the layer forming the fringes (1). (3) indicatesthe (total) length of a fringe (H), (4) indicates the depth of thehollow center or inner height (H_(n)), (5) is the diameter at the bottomof the fringe (D), and (6) is the (inner) diameter of the hollow center(D_(1/2)) at half height (H_(n)/2) (7).

As used herein, the fringe length or height (H) is the average maximum(vertical) distance between a (base) valley adjacent to the fringe whoseheight is determined and the tip of said fringe. It is readily apparentthat the height should be determined on fringes in their most possibleupright or vertical position, rather than on bent over or down-lyingfringes. A particular fringe may be higher on one side. The fringesshould have a minimum height of at least about 40 micrometers (microns)or more, preferably of at least about 80 microns or more, mostpreferably of at least about 150 microns or more. Typically, the fringeheight is less than about 1 millimeter, preferably less than 600microns. Most preferably, the fringe height is in the range of fromabout 200 to about 400 microns.

The particular geometry of the fringes can further be characterized interms of the depth or height and diameter of the inner hollow part.These parameters can be put in relation with the overall fringedimensions.

The values for H_(n), D and D_(1/2) can be calculated from the profileheight function as determined by optical surface profilometry. Thesestructural parameters can also be measured from the two-dimensionalcross-sectional view of the fringe structure when the cross-section isdissecting the center of the hollow fringes as schematically illustratedin FIG. 1.

The hollow depth ratio (●) is defined as the ratio of the average innerheight or average depth of the hollow center (H_(n)) to the average(maximum) height of the fringe (H) (●=H_(n)/H). The depth of the hollowcenter (H_(n)) may exceed the (outer) height (H) of the fringe, yieldinga hollow depth ratio (●) of more than 1. Preferable, ● is below 1.3,more preferably below 1.2.

The hollow diameter ratio (●) is defined as the ratio of the diameter ofthe hollow center at half (inner) height (D_(1/2)) and the diameter atthe bottom of the fringe (D) (●=D_(1/2)/D). The diameter at the bottomof the fringe (D) is determined at the point of inflection at which thevertical portion of the fringe starts. While the ratio may be higherthan 1, fringe structures with values of about 1 or lower are preferred.At least partially hollow craters characteristic of the fringed surfacemicrostructure of the present invention preferably have a hollowdiameter ratio of at least about 0.1 or higher. In case the hollowdiameter ratio is higher than 1, the measurements should be determinedby optical microscopy.

The hollow depth ratio (●) and the hollow diameter ratio (●) are used tocalculate the Hollowness Index (●). The Hollowness Index is indicativeof the degree of hollowness, or the unfilled volume at the top of thefringe. The Hollowness Index (●) is calculated by multiplying the hollowdepth ratio (●) with the hollow diameter ratio (●)(●=●×●×100=H_(n)/H×D_(1/2)/D×100). The Hollowness Index (●) is typicallyabout 15 or higher, preferably about 25 or higher, more preferably 40percent or higher. The Hollowness Index may be more than 100 (e.g., incase (●) is higher than 1). The Hollowness Index should be below 260,preferably below 130 preferably, more preferably the Index is 100 orlower, most preferably about 90 or lower. For the purpose of the presentinvention, fringes having a Hollowness Index of 100 or higher areconsidered as being completely hollow.

Another parameter suitable to characterize the fringe structure is thetotal surface area which depends on the fringe height (H), thehollowness, the diameters (D and D_(1/2)) and the density of thefringes. The Surface Area Ratio can be obtained by optical surfaceprofilometry. Generally and as evident from FIG. 1, an at leastpartially hollow fringe according to the present invention has a greatersurface area than a corresponding solid fringe (having the same outsidegeometric dimension).

Another parameter useful to characterize the fringe structure is theaspect ratio (A). The aspect ratio (A) is the ratio of the fringe height(H) and the fringe diameter (D) (A=H/D). Preferably, the fringes have anaspect ratio of between about 1 and about 5, most preferably betweenabout 1 and 3.

Another parameter characterizing the fringed surface microstructure isthe center-to-center distance between two adjacent fringes. Preferably,the center-to-center distance is from about 100 to about 300 microns.

The particular three-dimensional fringed surface configurationcharacterizing at least one layer of the film, sheet, or coatingaccording to the present invention may be obtained starting from asuitable precursor film, sheet, or coating. The structure of saidprecursor is characterized by a distinct surface texture consisting in apattern of different (surface) thicknesses, i.e. areas of reducedthickness (valleys or troughs) and areas of greater thickness (peaks orprotrusions). Advantageously, this pattern is predetermined and may beirregular or regular.

Alternatively, the precursor may be a foamed structure, e.g. a film,sheet, or coating having a foamed surface layer. In such case, theprecursor protrusions are formed by the microbubbles of the foam. In thefollowing, a film, sheet, or coating characterized by such pattern ofdifferent surface thicknesses and suitable to give a fringed surfacemicrostructure according to the present Invention will be referred to as“precursor” (film, sheet, or coating). This includes a film, sheet, orcoating which in part is characterized by such pattern of differentsurface thicknesses.

To obtain the fringed surface microstructure the precursor surface ismechanically treated such that the protrusions are essentiallylongitudinally extended. Preferably, such longitudinal extension orstretching of the precursor protrusions is the result of treatment usingmechanical means, such as a mechanical pulling force and/or an abrasivedevice.

The mechanical treatment of the precursor film, sheet, or coating ispreferably performed in an in-line process, meaning that formation ofthe precursor structure and the fringed surface microstructure occur ina single continuous process. Such in-line process involves a matrixsurface suitable to create a surface texture and comprises formation ofthe precursor film, sheet, or coating on the matrix surface in acontinuous compression molding process and subsequent formation of thefringed surface microstructure when the film, sheet or coating is pulledoff the matrix surface under certain conditions.

The matrix surface, for example a moving belt or a roller surface,presents a negative or reverse approximation with respect to the desiredsurface texture of the precursor such that the thermoplastic materialclosely contacts said reverse structure under pressure. The negativestructure may, for example, consist of very fine cavities. The cavitiesmay have various geometries—primary variables include cavity dimensions(diameter, depth), shape and entry angle (with respect to the matrixsurface). Advantageously, the surface temperature of the moving belt orroller is adjustable.

In such a continuous process, mechanical treatment resulting in thelongitudinal extension of the precursor protrusion occurs during theremoval or peel-off of the precursor film, sheet, or coating from thematrix surface by exerting on the protrusions a tractive force at acertain angle. Appropriate control and defined conditions for themechanical treatment are essential to make a fringed surfacemicrostructure according to the present invention.

Mechanical post-treatment of the thus obtained fringed film, sheet, orcoating, for example with an abrasive material, is optional, but may bedesired to enhance fringed surface characteristics and properties. Theadditional mechanical deformation by means of an abrading device shouldaffect, for example, the fringe length and/or the texture of the fringetips.

Suitable equipment for such continuous compression molding process tomake a fringed film, sheet, or coating comprises a set of surfaces, aspresented for example by a pair of rollers, preferentially enablingtemperature control, with defined surface qualities. The surfaces mayhave different, similar or equal surface roughness and shape. Thesurfaces may be part of the primary equipment used to make the (base)film, sheet, or coating, or, preferably, be installed for a secondary(separate) compression molding process. At least one surface, referredto as matrix surface, is characterized by the presence of numerouscavities with a projected area of at least about 1000 square microns anda depth of at least about 100 microns. The number or density of cavitiesshould correspond to the desired fringe number or density. Such matrixsurface structure can be provided by a porous material, an open cell,foamed material, by woven or entangled fibrous structures (e.g.,natural, metallic, polymeric), by sintering of a suitable material, suchas metallic, ceramic, polymeric or natural particles, or fibrousmaterials, by mechanical or chemical treatment of a suitable material,or preferably by eroding techniques (electrical, chemical, lasering).Preferably, the cavities are substantially regular or symmetrical.

Preferred matrix surfaces are steel, a rubber, e.g. covering anappropriate support, such as a steel core, a polymer, e.g. coated on anappropriate support, such as a steel, or a ceramic, e.g. on anappropriate support, such as steel. A particularly preferred matrixsurface is a rubber, advantageously having a Shore A hardness in therange of about 70 to about 85, preferably a halogen-elastomer, such as afluoroelastomer. Advantageously, the matrix surface is lasered with finecavities having or approximating the form of cylinders.

Suitable techniques and technologies to make the matrix surface and thecavities are known in the art. The matrix surface is applied on a devicesuitable for processing a film, sheet, or coating, such as a roller or abelt. Typically, for symmetrical cavities, such as cylinder-likecavities, the angle of incline of the axis of symmetry of the cylinderrelative to the matrix surface is in the range of from about 45 degreesto about 90 degrees, preferably 90 degrees.

To prepare the desired precursor having a pattern of different surfacethicknesses a polymer mass, e.g. in the form of a polymer melt, polymerdispersion, polymer suspension, polymer solution, film, sheet, orcoating is applied on the matrix surface. Advantageously and preferably,the polymer mass is applied in form of a semifinished product, inparticular in the form of a film, sheet, or coating. If desired,lamination (to that surface of the semi-finished product which is notfacing the matrix surface) may be accomplished simultaneously with thecontinuous compression molding step. One or more counter surfacessuitable to apply pressure onto the polymer mass, such as a roller or abelt, is used to force the polymer mass into the cavities of the matrixsurface. Preferably, penetration of the polymer mass into the cavitiesis facilitated by heating the surface of the mass to a temperature whichis close to, preferably above the melting point of the polymer formingthe protrusions. Generally, the person of ordinary skill in the art isreadily able to select the appropriate temperature. The surface of thepolymer mass is molded such that individual, distinct surface elevationsor protrusions are formed in the cavities, thus yielding a suitableprecursor structure. At the same time, the other surface of the polymermass is shaped according to the structure of the counter surface of thepressuring device. The surfaces of the precursor reflect the surfacecharacteristics of surfaces, e.g. both rolls, the pressure roll and thematrix roll. Key parameters during formation of the precursor are rollpressure and temperature (of the polymer mass surface and the relevantequipment). Low(er) viscosity of the polymer is preferred. After thesurface molding, the film, sheet, or coating is released or pulled offfrom the matrix surface, which step requires sufficient (tensile)strength to pull the molded elevations out of the cavities. Sufficientstrength is achieved by appropriately cooling the precursor, if desiredusing additional external cooling sources, such as an air knife orcooling water. Preferably, the thermoplastic material is not solidified,when the fringe-forming force is applied and the film, sheet or coatingis stripped off the matrix surface. Most preferably, thermoplasticmaterial is in the semi-molten state when the film, sheet or coating isstripped off the matrix roll. Advantageously, the film, sheet or coatingis cooled such that the thermoplastic material forming the fringes has atemperature which is about at or advantageously below the Vicat point.If the polymer mass fed into the compression molding equipment is asuspension or emulsion (additional) drying and/or curing and/orcross-linking may be performed on the matrix roller or belt, optionallyin the presence of additional sources of energy for curing orcrosslinking after the surface molding has occurred.

During the release process of the precursor from the matrix surface, theprotrusions characterizing the precursor surface are elongated to givethe fringed surface microstructure. Thus the mechanical treatment of theprecursor providing deformation of the protrusions involves subjectingthe precursor and the protrusions to a tractive force. The tractiveforce is dependent on adhesion or interaction between the polymercomprising the fringe layer and the matrix roll surface and the releaseangle.

A crucial parameter in this step of mechanical treatment is the releaseangle, that is the angle between the fringed film, sheet, or coatingduring the release process and the matrix surface. In this contextmatrix surface means that part of the device which is free and no morecovered with the film, sheet, or coating. In case the matrix surface is(on) a roller, the release angle is the angle between the fringed film,sheet, or coating and the tangent through the point of release. Therelease angle should be greater than 10, preferably greater than about20 degrees, more preferably at least about 45 degrees and mostpreferably at least about 90 degrees. The release angle should be lessthan about 170 degrees. The release angle is impacted by the angle ofthe cavities in relation to the surface. The temperature at the polymersurface should be above the glass transition temperature and below thecrystalline melting point of the polymer forming the protrusions.Release angle, take-off speed and polymer surface temperature areselected such as to further extend the protrusions of the precursor,thus still further increasing the surface area in respect to theprecursor structure.

A preferred process to make the fringed film, sheet or coating of thepresent invention is a roller-based continuous compression moldingprocess. Such process comprises a (cavity) filling step and a release orpeel-off step, both of which affect fringe formation. In the preferredprocess, the matrix roll is in contact with a pre-heat or counter roll,forming a nip. The nip width depends upon the compression of either orboth of the counter (or preheat) roll and the matrix roll at thetemperature and pressure applied. The linear compression distance at thecenter (axis) of the rolls is the negative gap. The pressure in the nipcan be measured according to methods known in the art. The arrangementof the rolls may be vertical or horizontal.

FIG. 2 schematically shows an example of a calander with vertically rollarrangement) suitable to make the fringed film, sheet or coating of theinvention.

So-called base film, sheet or coating is fed from a feeder roll (10)onto a pre-heat roll (11) representing the counter surface. Preferably,at least those parts of the base film, sheet or coating desired to beconverted into a fringed surface microstructure have a (relatively)smooth surface. Advantageously, the temperature of the preheat roll (11)is at or above the melting point of the polymer forming the fringedsurface. The base film, sheet or coating contacts the pre-heat roll (11)for a predetermined distance. If appropriate, and depending on thedesired polymer temperature in the nip, the contact distance can beincreased or reduced by means of one or more idler rolls (12) which setthe point of initial contact on the preheat roll. The nip width dependsupon the compression of either or both of the preheat roll and thematrix roll (13) at the temperature and pressure applied. The pressurein the nip can be measured according to methods known in the art.

The actual amount of preheat time that the film, sheet or coatingexperiences prior to the nip will be dependent upon the distance thatthe film wraps the preheat roll and the line speed, and any additionalheat that may be supplied via auxiliary methods, such as infraredheating of the surface of the film, sheet or coating. The temperature ofthe particular polymer layer coming in contact with the matrix roll (13)preferably is at or above the melt temperature of the polymer when itleaves the nip contact width. For blends, the temperature should be suchthat the majority to all of the polymer is molten. Critical variables inthe ‘filling step’, i.e. in the filling of the matrix cavities, whichaffects fringe formation include polymer type, and (its response to)line speed, temperature in the nip, and pressure in the nip.Advantageously, these variables are measured ard/or controlled usingconventional methods known in the ant. For example, nip contact pressurecan be measured using commercially available pressure measuring film,e.g. Fuji Prescale Film. Maximum nip pressure measured at the center ofthe rip width in line with the canter of the roll axis should be atleast about 1 MPa, or higher. The gap between the two rolls (11) and(13) should be negative. Another critical parameter is the interactionof the polymer and the matrix roll surface. The polymer should havesufficient wettability to the matrix roll. The filling step yields theprecursor which is then cooled as it travels along the matrix roll.Release from or peel-off of the matrix surface (release step)advantageously involves a take off system, for example comprising achill roll (15) and a winder (16). Optionally, a device supportingcooling of the film, sheet or coating on the matrix roll, such as an airknife (14, may also be present. Such devices serves to facilitate realof the film from the matrix roll, or to increase production speed. Theamount of force/tension required to peel the film, sheet or coating fromthe matrix roll for a given fringe layer polymer is dependent upon theadhesion of the polymer to the matrix tol surface (which is a functionof the composition of the matrix roll surface and the polymer, and theirtemperatures), and the release or peel angle. FIG. 3 illustrates thedetermination of the peel angel (β).

The greater the adhesion, typically the higher resulting peel angle. Forhollow fringe formation, it is important optimize the adhesion, linespeed and strength of the precursor so that a maximum amount of draw orelongation of the fringe layer polymer is obtained, while ensuring thatthe polymer is completely removed from the cavity due to an adhesive pee(or controlled adhesive failure) between the polymer and the matrixsurface. This results in hollow fringe formation with optimized fringedlength.

In order to avoid sticking of the film, sheet, or coating according tothe invention to the equipment used in making said item or to facilitaterelease of the item, it may be desirable to use a sacrificial backinglayer or protective layer. The sacrificial layer can be, but not limitedto, oriented or non-oriented PET film, aluminum foil, non-woven/fleece,oriented or non-oriented polypropylene film, oriented or non-orientedpolystyrene film, oriented or non-oriented PLA (polylactic acid) film,or natural fiber substrates, and/or a ‘release aid’, such as PTFE,silicon, etc. as equipment coating materials (e.g. on the pressure rollor counter roll), or plasticizer or migratory additives in the polymermatrix (fatty acids, etc.). Film or sheet exhibiting a melting pointwhich is at least 20° C. higher than the fringed layer material aresuitable as sacrificial layers.

Advantageously and preferably, the thermoplastic polymer or polymerblend forming the fringed surface microstructure is selected such thatthe fringes (after formation) are dimensionally stable, resilient andresistant to deformation under load at ambient temperature. Generally,polymer selection will be dictated by the particular process conditionsfor making the precursor and the fringed surface and the specificperformance requirements of the envisaged end-use applications. Optimalfilling of the cavities with the polymer is favored by employing athermoplastic having a low viscosity at the relevant processingtemperature.

Preferred polymers for use in the fringed layer obtainable by theabove-described process combining optimal filling in the continuouscompression molding processs and mechanical treatment by application ofa tractive force are polyolefins more preferably ethylene-basedpolyolefins, including homogeneous ethylene-based polymers andheterogeneous ethylene-based polymers, such as Ziegler/Natta polymershaving a density in the range of about 0.900 g/cm³ to about 0.960 g/cm³(e.g. DOWLEX™ or ATTANE™ copolymers available from The Dow ChemicalCompany), or polymers produced via high pressure processes.

Optionally, the fringed film, sheet, or coating thus obtained may besubjected to mechanical post-treatment, such as treatment relying on theprinciple of friction, for example treatment with an abrasive device.Preferably, the abrasive device has a harder surface or surface coatingthan the polymer surface to be treated. Suitable abrasives include, butare not limited to, sandpaper or sand-paper type materials, brushes,steel wool, or abrasive fabrics, such as a fleece or a non-woven havingthe required surface hardness. Suitable materials for the brush are, forexample, nylon, glass-fiber or metal wire, such as bronze. It is readilyapparent to the person skilled in the art that the length of the fringesis affected by the type of abrasion material and the particulartechnique of treatment therewith. Critical parameters include deformingspeed, applied pressure, temperature, particularly the polymer surfacetemperature, and hardness (difference). Advantageously, the treatment issuch that the fringed surface structure is enhanced, e.g. the fringestructure is elongated and the tips may become frayed. Best results areobtained by circular, oscillating or linear movements, or anycombination thereof. The general direction of these movements relativeto the fringed surface and surface orientation may be longitudinal,transverse, angled, or any combination thereof. If the treatment isessentially unidirectional, it is preferred to have at least twoconsecutive steps of either unidirectional or angled treatment. In thecase of rotational or oscillating treatment, sequential treatment stepscan improve the final quality of the surface. For each combination ofsurface hardnesses, i.e. surface hardness of the abrasion material andsurface hardness of the polymer surface, exists an optimum type ofmovement and speed to obtain a particular fringed surfacemicrostructure, e.g. fringe length and Hollowness Index. Suchoptimization is within routine experimentation. When magnified, e.g.using the SEM technique, the tops of the walls of the craters may beseen to be frayed, tom and elongated.

A film fed into the above described compression molding process can bemade by any known process including, but not limited to, solvent casting(for example, dispersion in a solvent, solvent including an aqueousmedium), extrusion (for example, blown or casting), compression (forexample, molding), roll milling or calendering, or any combinationthereof. Extrusion as used herein is intended to include co-extrusion,extrusion coating or any combination thereof. One or more films may belaminated to form a multi-layer structure. Also, a film may be laminatedto a woven or non-woven fabric forming a composite structure.

One or more layers of the film may be expanded, for example with aconventional blowing agent, to make a foamed film. To make foamed filmstructures or layers, either physical or chemical blowing agents may beused to achieve suitable foam densities, e.g. foam densities from 1g/cm³ to as low as 0.01 g/cm³. Suitable blowing agents are known in theart the foams may be open or closed cell, according to ASTM D2856. Thecell sizes of the foams typically are from about 0.01 mm to about 5.0mm, preferably from about 0.02 to about 2.0 mm. The foams may becrosslinked or non-crosslinked.

A sheet can be made by any known process including, but not limited to,solvent casting, extrusion, roll milling, compression or calendering, orany combination thereof.

A coating can be made according to methods known in the art, e.g. byextrusion coating or involving a roller and doctor blading.

Fringed films, sheets, or coatings, and articles of manufacturecomprising such fringed film, sheet or coating particularly benefit fromthe fringed surface microstructure. Performance attributes which can bespecifically provided or enhanced by the fringed surface microstructureinclude soft, velvety and textile-like feel or touch, matte appearance,liquid repellency, anti-skid and good grip properties, surfacevariability and surface imprintability, controlled release properties,storage capabilities, and protective properties. Depending on theintended end-use application the fringed surface microstructure can bedesigned and optimized to specifically exploit or favor one or more ofthese performance attributes, for example by selection of a properpolymer material or polymer materials, and/or of a proper fringestructure. If desired or required, the fringed film, sheet or coatingmay be made to provide additional functional properties, such asbreathability, increased heat resistance, or barrier properties.

The present invention also relates to an article of manufacture madefrom or comprising a fringed film, sheet or coating. Based on thespecific advantageous performance attributes afforded by the fringedsurface microstructure such articles of manufacture are useful, forexample, for decoration or as decorative materials, for packaging or aspackaging material, for use as labels or signs, in automotiveapplications, for industrial, personal or medical hygiene applications,for apparel or protective clothing, and for household applications.

More specifically, the fringed surface microstructure characterizing thearticles of the invention affords an excellent soft, velvety andtextile-like feel or touch, the fringed film, sheet, or coating of thepresent invention has improved haptics and is very pleasant and easy ona person's skin. Based on this property such fringed film, sheet, orcoating is useful to manufacture plastic based articles for which suchimproved haptics are desirable, e.g. plastic articles of manufactureused in soft touch, soft feel applications. For example, soft touch,soft feel materials are desirable in the automotive industry, forexample on automotive interior surfaces, including but not limited toinstrument panels, console liners, door panels, seat covers, headliners,and steering wheel covers. The fringed films, sheets, or coatingsaccording to the invention are also useful to make decorative fabrics orarticles with (direct) skin contact, for example, furniture coversincluding outdoor furnishing, such as desk covers, cushions, includingpatio air cushions, drapes, bedspreads, and table cloths; ostomy bags;mattresses including air mattresses; life vests; artificial leather;floor covering; medicinal and personal hygienic articles, including forexample bandages, band aids, condoms, incontinence articles, such asdiapers, or parts thereof including e.g., top sheet, ears or wings,cuffs, side panels, and back sheets; (disposable) garments apparel, andprotective gear; such as medical drapes and gowns, athletic clothing,raincoats, hats and caps; grip bands; (bag) handles; linings, forexample for luggage, bags or handbags, or shoes; gloves, and protectivegear, artificial skin, skin imitations, toys, industrial hygienicarticles, such as wipes or disposable toilet seat covers, head restcovers and the like. For end-use applications requiring a soft feel thefringe length is advantageously at least about 150 microns or more.Generally, use of polymers having a low modulus polymer will beadvantageous to obtain a soft feel. The use of polymers having a highermodulus will result in differentiated haptics and tacticity, affording a(relatively) rough feel rather than a soft feel. Such articles can beuseful as scouring or abrading devices, or to provide anti-skidperformance.

Another benefit provided by the fringed surface microstructurecharacterizing the film, sheet, or coating according to the invention isa matte (mat) appearance and further reduced gloss (relative to theprecursor). Gloss is determined according to ASTM D2457. The films,sheets, or coatings according to the invention are useful to manufacturearticles relying on excellent aesthetics and matte optical appearanceincluding, for example, decorative overlays, including wall, floor, orceiling covering products; artificial flowers; linings of jewelry boxesand luggage; anti-glare surfaces such as billboards and window clingsings, merchandise bags, and projection and movie screens.

Another advantageous property characterizing the fringed film, sheet, orcoating is a differentiated surface tension, as determined by the testmethods according to ASTM D-2578 or DIN 53364, and water contact angle.The fringed films, sheets, or coatings of the invention are useful forapplications and articles where surface water or liquid drain managementsuch that water beads up and drains off, is required, such as clothingwith liquid repellant surfaces, e.g. rain gear, such as hats, coats, orponchos, protective clothing, feminine hygiene top sheet, (disposable)table cloth and shower curtains.

Furthermore, the fringed surface microstructure also provides africtional behavior, as reflected e.g. in the dynamic coefficient offriction, which affords anti-slip or anti-skid and better gripperformance attributes to a fringed film, sheet, or coating, or anarticle of manufacture with a surface made from or comprising a fringedfilm, sheet, or coating of the invention. The dynamic coefficient offriction of a particular fringed surface may be determined according toISO 8295, relative to various surfaces of interest, including, forexample, the same or a different fringed surface, or a glass, metal,ceramic or polyolefin surface. The fringed surface microstructureprovided herein typically provides an increased coefficient of frictionas compared to non-fringed (plain) film of the same composition. Thebetter grip and anti-slip properties make the fringed film, sheet, orcoating of the invention useful for a variety of applications andarticles including, but not limited to floor cover backings, furniturecovers, gloves, table wear, bathroom articles, such as shower shoes andshower mats, roofing, tarps for construction, truck bed covers, boxcoatings, self-adhering closing systems, e.g. VELCRO™-like systems,serving trays (e.g. as used in air planes or restaurants), grip bands ortapes, and non-skid operation room table cover.

The process for making gloves comprises dipping hand forms into asuitable dispersion, such as latex. The hand forms are cleaned, rinsedand dried. Subsequently, the forms are heated and a coagulant for thelatex is added to support curing of the latex. The latex is applied tothe forms by dipping the forms into the latex bath. Before the productis cured any undesirable solvents or materials are allowed to leach outduring a leaching step. The gloves may be removed from the form byblasting them off by air, which is rather difficult to accomplish, or bypeeling the latex off the form while inverting it at the same time.Prior to the curing or leaching steps, the gloves may be dipped into abath for coating with another material. For example, the coating mayserve to enhance grippage, increase the wearer's ability to hold ontoslippery or wet instruments or improve the feel against a person's skin.The continuous compression molding process according to the presentinvention can advantageously be used to make gloves with a fringedsurface microstructure. In such process, the forms are employed asmatrix surface. The peel/inversion process to remove the gloves from theform is applied such as to give the fringed surface micro-structure.Thus the secondary dipping step of the conventional process becomesredundant.

Another benefit afforded by the fringed surface microstructure issurface variability, particularly surface printability or imprintability(embossing), as reflected in the possibility to create distinct areas ofdifferent topography, e.g. using suitable impression techniques. Thefringed surface may be (im)printed with or without ink. Printability maybe evaluated in terms of ink adhesion, color density (vividness), printdefinition employing suitable methods known in the art, including forexample adhesive tape peel tests, abrasion tests, or simply visualappearance. The ink may reside inside and/or between the fringes as wellas at the tips or sides of the fringe. Acceptable ink adhesion ispossible for water based and solvent based inks and should be selectedbased on the fringe layer polymer. Color density may vary dependent onthe angle of view thus creating a unique 3D-type appearance. Clearfringed film may be reverse printed, e.g. by printing the fringedmicrostructure and viewing from the reverse side.

Using, for example, a hot stamp, hot air or friction to re-melt and/orcompress part of the fringes in a selected regular or irregular patternto form a smooth surface, haptic and/or optic effects are achieved bythe resulting difference in surface structure and appearance. Thusprinting effects may be obtained without the need for color or ink. Ifthe difference in surface structure is marked, it may also be noticeableby a person with reduced visual ability or a blind person. Nevertheless,color or ink may be added to enhance the effects.

The desired imprinting effects may be realized relying on the sameprinciples used in printing or sealing. For example, a stencil or printnegative which is a metal or thermoset material that can be heatedwithout distortion to temperatures above the melting point of thethermoplastic polymer forming the fringes may be employed. Suitabletemperatures for polyethylene are in the range of from about 50° C. toabout 200° C., preferably from about 60° C. to about 160° C., morepreferably from about 70° C. to about 120° C. The image or pattern ofthe stencil or print negative is applied by pressing it on the fringedsurface such that a three-dimensional effect is obtained. The effectsare also obtainable in a process which does not involve contacting thefringed surface, e.g. by applying a jet of hot effluent (e.g. air)similar to an air brushing printing process. Another process suitable toobtain imprinting effects is to abrade the fringes on the surface by amechanical process and thus create areas of differentiated topographyresulting in print-like images. Alternatively, to obtain the describedeffects, the fringed surface may be created only on parts of the basicfilm, sheet, or coating ‘a priori’.

The fringed surface microstructure can be printed with ink and resistink from being scratched or abraded, thus enhancing the durability andappearance of the fringed article or item. The benefit of enhancedabrasion and scratch resistance is also afforded to coatings, such asbarrier coatings, or metallization. By making the (barrier) coatings ordeposits more scratch and abrasion resistant their particular propertieswill be maintained for a longer period of time. The advantage ofimproved scratch resistance also applies to printed or painted surfaces,e.g. in an automobile, such as dash boards, instrument panels etc.,metallized films, e.g. used in the packaging of food, medical items orelectronics, and barrier coated films.

Based on its surface variability and/or imprintability the fringed film,sheet, or coating of the present invention is particularly useful tomake novelty balloons, book covers, wrapping paper, floor covering,ceiling covering or wall covering, labels, including, for example,in-mold labels and stretch labels, e.g. for bottles, bill boards, orpaperboard coatings, e.g. for drinking cups, greeting cards, and partyarticles.

The increased surface area of the fringed film, sheet, or coating of theinvention affords enhanced carrying, capturing or storing properties,which can be exploited for numerous applications and articles, includingbut not limited to articles comprising a controlled release system. Forexample, such system may provide for the controlled release ofantibiotics and may be useful e.g. in wound covers or shower curtains,the controlled release of fragrances or the controlled release of drugs.Enhanced carrying, capturing or storage properties can also be exploitedin wipes, tissues, carrier substrates for catalysis, filtration media,diaper top sheets, e.g. coated with diaper rash ointments, antistaticsheets, anti-fog films, and for HF weldability, thermal insulation,sound deadening, meat packaging and poultry diapers. Craters which areat least partially hollow provide a greatly enhanced surface area (e.g.as compared to a filled protrusion). The hollow tube structure has anoutside surface, an inside surface, as well as the surface between thehollow tubes. The craters are suitable reservoir structures, which othersubstances can be embedded into or coated onto. Such reservoirstructures allow, for example, the gradual diffusion or the controlledrelease of substances, such as drugs or fragrances. Such reservoirstructures are useful e.g. in transdermal drug delivery systems,fragrance delivery systems, such as soft packages for cosmetics orperfumes, scented wall covering, or as filtration systems. A porousmembrane may be put over the top of the reservoirs to allow the softsurface to breath to the skin (drugs) or air (fragrances). If a barrier,for example made from SARAN™ or EVOH resin, is coated over the top ofthe reservoirs and the base of the film is made from a porous materialthe drug is delivered through the base polymer. Emollients or salves canbe placed in the reservoirs to maintain moistness for burn wounds or fordiaper rash creams with the soft side against the skin. Antibacterialagents can be placed on the surface to prevent mold and mildewformation, e.g. in shower curtains. Placing a static charge on thesurface further enhances the ability to pick up substances, such as dirtor dust.

Furthermore, absorbent materials can be coated onto the fringed surfaceor be incorporated into the polymer (as a type of filler) before thefringed film, sheet, or coating is made, for example in order to enhancethe absorption of coatings or ink. Examples of suitable absorbentfillers include, for example, superabsorbents used in hygieneapplications, talc and calcium carbonate.

The fringed film, sheet, or coating according to the invention may bemade to be (moisture) vapor permeable or breathable. For example,breathable films include filled and stretched microporous films, ormonolithic films, for example made from a thermoplastic polyurethane, acopolyesterether thermoplastic elastomer, a copolyesteramidethermoplastic elastomer or another highly water vapor transmittingpolymer, such as a polyamide. A (thin) fringed layer may be coextrudedon top of a previously stretched microporous layer or the fringed filmcan be stretched. A (thin) fringed layer can also be extruded on top ofan inherently breathable monolithic layer. Water vapor breathability isa performance attribute desired or required for use of the fringed film,sheet, or coating of the invention in apparel, such as protectiveclothing, or in hygienic articles, such as (diaper) backsheet.

For example, a breathable monolithic fringed film is characterized by ahigh water vapor transmission rate (WVTR) and has a soft touch. Inconventional breathable films, the soft touch has been provided bylaminating a non-woven to the film. If desirable, the breathablemonolithic fringed film may be laminated to another material whichprovides a different function in the composite, such as noise reductionor elastic recovery. Advantageously, the fringed surface microstructureis designed so as to provide the desired water repellency performance orliquid impermeability. Thermoplastic polymers suitable to make(inherently) breathable fringed film include, for example, polyetherblock copolymer (e.g., PEBAX™ copolymer), and thermoplastic polyurethane(e.g., PELLETHANE™ polymer). The films may be mono-layer or multi-layerstructures, preferably each layer having a high WVTR. The WVTR measuredat 38° C. and at 90% relative humidity (using ASTM method E96) should bein the range of 500 to 10,000 g/m²/day, more typically in the range of1000 to 6500 g/m²/day. Such film is suitable for apparel or otherapplications for which breathability is desirable, including athleticwear, side panels in diapers or adult incontinence products.

The fringed films, sheets, or coatings according to the invention areuseful for packaging applications, e.g. packaging applications requiringenhanced protection, e.g. against scratching, or cushioning, and/orprintability. Exemplary packaging applications include pouches, e.g.pouches for flowable materials, such milk or detergent pouches, bags,e.g. boutique bags, and protective covers, e.g. for cars, bikes orboats. Fringed film, sheet, or coating comprising poly(lactide) areparticularly suitable for disposable articles.

The fringed film, sheet or coating may be elastic. The elastic film ofthe invention comprises a material which is highly stretchable and whichreverts to its original or nearly original form upon release of anypressure or force applied to the film material. In a preferredembodiment, the elastic film, sheet or coating of the invention achievesat least about 50 percent of its stretched length after the first pulland after the fourth pull to 100% strain (doubled the length). Recoveryrefers to a contraction of a stretched material upon termination of aforce following stretching of the material. Percent recovery may beexpressed as: [(maximum stretch length−final sample length)/(maximumstretch length−initial sample length)]×100. Elasticity can also bedescribed by the “permanent set” of the film. Permanent set is theconverse of elasticity. A film is stretched to a certain point andsubsequently released to the original position before stretch, and thenstretched again. The point at which the elastic material begins to pulla load is designated as the percent permanent set. Elastic polymericmaterials include, for example, AB and ABA block or graft copolymers(where A is a thermoplastic endblock such as, for example, a styrenicmoiety and B is an elastomeric midblock derived, for example, fromconjugated dienes or lower alkenes), chlorinated elastomers and rubbers,ethylene propylene diene monomer (EDPM) rubbers, ethylene-propylenerubbers, thermoplastic polyurethanes, ethylene-alpha olefin copolymers,specifically at a density less than 0.89 g/cc, and ethylene-styreneinterpolymers with a styrene content of less than 40 weight percent.Blends of these polymers alone or with other modifying elastic ornon-elastomeric materials are also contemplated being useful in thepresent invention. The low modulus of elastic films is also advantageousin terms of haptics.

In a post-treatment step, the fringed film, sheet or coating accordingto the invention may be oriented according to methods known in the art.

If desired, the fringed film may be further treated (post treatment) andthe surface characteristics of a fringed film may be modified bytechniques known in the art, including, for example, corona treatment.Corona treatment increases the polarity of the surface, thus increasingthe wetting tension. The greater the polar component the more activelywill the surface react with different polar interfaces.

One aspect of the present invention relates to a mono-layer film, sheet,or coating, or articles of manufacture comprising such film, sheet, orcoating, characterized by a fringed surface microstructure on one side,or on both sides. The fringed microstructure may cover parts of thesurface, or the entire surface. Such mono-layer structure is preferablymade from a suitable thermoplastic polymeric material indicated as beingpreferred herein-above. The mono-layer may be made from a singlethermoplastic polymer, preferably an ethylene-based polymer, includingfor example a heterogeneously or, preferably, a homogeneously branchedethylene polymer, and a substantially random ethylene/styreneinterpolymer, a polypropylene polymer, or a (poly)lactide, or a mixtureor blend of thermoplastic polymers, preferably comprising the polymersindicated as being preferred. For example, a suitable polymer blend maybe composed of two homogeneously branched ethylene-based polymers.

The present invention further provides a mono-layer or multi-layer film,sheet, or coating comprising a thermoplastic polymeric material, whereinthe film, sheet, or coating, the thermoplastic polymeric material orboth have been cured, irradiated or cross-linked. Advantageously,curing, irradiation or crosslinking is performed after forming of thefringed surface microstructure. Preferably, the cured, irradiated orcross-linked thermoplastic polymer is a polyolefin, most preferably anethylene (inter)polymer. Crosslinking is achieved using the methods andtechniques described in more detail herein-above. Such film, sheet, orcoating affords the benefit of enhanced heat resistance, as required,for example, by applications in the automotive industry, such asautomotive interior applications, such as steering wheel covers, orarticles with much exposure to the sun, such as outdoor furniturecushion covers.

Generally, in a multi-layer film, sheet, or coating according to theinvention, at least one layer has a fringed surface microstructure andis comprised of a thermoplastic polymer as defined herein. The fringedmicrostructure may be present on one or both sides of said layer orlayers. The fringed layer may be an inner and/or, an outer layer. Amulti-layer film, sheet or coating wherein the fringed layer is an outerlayer are preferred.

In a multi-layer structure, each layer will serve a particular functionor provide some characteristic to the overall structure. The compositionof these layers is chosen depending on the intended end use application,cost considerations, and the like.

For example, layers may serve to provide particular structural orfunctional characteristics, e.g. add bulk to the structure, promoteinterlayer adhesion, provide barrier properties, thermal properties,optic properties sealing characteristics, chemical resistance,mechanical properties, or abuse resistance. An adhesion promotinginterlayer is also referred to as a tie layer. If a barrier layer isdesired or required for the intended end use application, it is selectedso as to meet the targeted degree of gas or moisture (im)permeability.

Various materials can be used for these layers, with some of them beingused in one or more than one layer in the same film structure. Suitablematerials include, for example, nylon, ethylene/vinyl alcohol (EVOH)copolymers, polyvinylidene chloride (PVDC), polyethylene terephtalate(PET), oriented polypropylene (OPP), ethylene/vinyl acetate (EVA)copolymers, ethylene/acrylic acid (EM) copolymers, ethylene/methacrylicacid (EMAA) copolymers, LLDPE, HDPE, LDPE, graft adhesive polymers, suchas maleic anhydride grafted polyethylene.

For example, a gas barrier layer may be made from vinylidene chloridecopolymer, EVOH copolymer or SARAN™.

Examples of thermoplastic polymers appropriate for use in the seal layerinclude LLDPE, ULDPE, VLDPE, POP, EVA copolymer, EAA copolymer andionomers.

Thermoplastic polymers for use in the bulk layer are advantageouslychosen based on cost considerations and include recycled materials.Representative polymers are, for example, LLDPE, such as ethylene/butenecopolymers, LDPE, EVA copolymer, (recycled) HDPE, polypropylene polymersand blends thereof.

Examples of thermoplastic polymers appropriate for use in a layerproviding advantageous mechanical properties include, for example,ethylene/C₄-C₈ copolymers. The fringed multi-layer structures accordingto the invention typically consist of from two to seven layers.Preferred are multi-layer films having three or more layers.

Permeability may be provided by a porous membrane.

For example, it is within the scope of the present invention to providea multi-layer film, sheet, or coating including the following generaltwo-layer and three-layer structures, wherein the respectivecompositions of the layers are chosen from thermoplastic polymer resinswhich provide the requisite functional properties:

-   -   Fringed/Bulk    -   Fringed/Seal    -   Fringed/Adhesion    -   Fringed/Bulk/Seal    -   Fringed/Bulk/Adhesion    -   Fringed/Mechanical/Seal    -   Fringed/Mechanical/Adhesion    -   Permeability/Fringed/Barrier

For each of these general structures, further internal or externallayers may be added to promote inner layer adhesion or add bulk, asappropriate.

The present invention also relates to the use of a fringed film, sheetor coating, preferably a film, in a hygienic product, including adisposable hygienic product, such as feminine hygiene articles, bandagesand wound cover materials, and incontinence articles, for examplediapers.

The present invention also relates to the use of fringed film, sheet orcoating in geomembranes.

Furthermore, the present invention relates to the use of a fringed filmin medical ostomy bags, urological collection bags and other liquidcontainment pouches. Furthermore, the invention relates to medicinalcollection bags, such as ostomy bags, urological collection bags andother liquid containment bags or pouches comprising a fringed film,particularly a multi-layer coextruded fringed film. The fringed surfacemicrostructure is particularly advantageous and desirable for bags thatare worn by a person and are in contact with his or her skin. Ostomybags and urological collection leg bags are examples of patient-wornbags. In many commercial applications today, barrier films are combinedwith soft nonwoven textiles, such as spunbonded or meltblown polyolefinor polyester nonwovens, to provide a laminate structure that can providepatient comfort when worn in contact with the body. The use of fringedfilm to impart soft “nonwoven” or textile-like feel to a coextrudedbarrier film structure can result in elimination of a separate nonwoventextile from a laminated bag structure.

Of particular interest for incorporation of a fringed film arecoextruded barrier films that provide good oxygen, carbon dioxide andodor barrier properties. Barrier properties can be achieved by use ofconventional barrier polymers such as polyvinylidene chloride (PVDC,such as SARAN® resin from The Dow Chemical Company), ethylene-vinylalcohol (EVOH, such as EVAL® resin from EVAL Company of America), nylonor amorphous nylon (such as GRILON® or GRILAMIDE® resin from EMS-Chemie,CAPRON® nylon from Allied Chemical or MXD6® nylon from Mitsubishi GasChemical Company), polyester (PET and PETG, such as EASTAR® polyesterresins from Eastman Chemical Company) or phenoxy (such as BLOX®thermoplastic epoxy resins from The Dow Chemical Company). In producinga coextruded barrier film, it is desired to provide outermost filmlayers that provide strength and sealability such as with polyolefinresins. Suitable polyolefin resins include low density polyethylene(LDPE), linear low density polyethylene (LLDPE), high densitypolyethylene (HDPE), metallocene or plastomer polyethylene (mPE),ethylene-styrene Interpolymers (ESI), ethylene-vinyl acetate (EVA),ethylene methyl acrylate (EMA), ethylene-acrylic acid (EAA), andpolypropylene homopolymer (PP) or polypropylene copolymer (coPP),chlorinated polyethylene (CPE), thermoplastic polyurethane (TPU),styrenic block copolymers such as styrene-butadiene-styrene (SBS) andstyrene-ethylene-butylene-styrene (SEBS). These resins typically havepoor affinity for and adhesion to the various barrier resins,necessitating the use of suitable tie layer resins to bond the layerstogether. The layers may include polyolefin copolymers that are polarmonomer modified, such as ethylene copolymers with 1 to about 40 weightpercent of polar comonomer. Suitable ethylene copolymers include EVA,EMA, EAA, ethylene-n-butyl acrylate (EnBA), and maleic anhydride (MAN)grafted polyolefins such as PE-graft-MAH, PP-graft-MAH andEVA-graft-MAH. These resins typically have 0.05-1.4 weight percent MAHgrafted onto the polyolefin polymer.

Barrier films of the present invention are typically about 1.0 mils (25μm) to about 10 mils (250 μm) in thickness, and preferably about 2.0mils (50 μm) to about 6.0 mil (150 μm) in thickness. Thicknessessignificantly greater than the preferred range can result is ostomy bagsor collection bags that are stiff and inflexible, resulting in poorconformation to a patients body. This results in uncomfortable wearingof the bag, as well as aesthetically unacceptable bulging or protrusionof the bag from under the patent's clothing, eliminating thediscreteness of wearing the appliance. In order to achieve good barrierproperties, a typical barrier film will have a barrier layer of at leastabout 0.2 mils (5 μm) in thickness.

Suitable film structures Include, for example, a symmetrical five-layerfilm with a core barrier layer, adjacent adhesive layers on either sideof the barrier layer, and outermost skin layers on each side of thefilm. Such multi-layer structure can symbolically be represented as a“ABCBA” structure, wherein the “C” layer is a barrier layer, the “B”layers are adhesive tie or bonding layers, and the “A” layers are skinlayers. A representative 4.0 mil (100 μm) film might have a “C” barrierlayer of PVDC or EVOH or PETG at 10% of the overall gauge; “B” adhesivetie layers of EVA or EVA-g-MAH at 10% each of overall gauge; andoutermost “A” skin layers of LLDPE, mPE or coPP at 35% each of theoverall gauge. This can be represented as a 35/10/10/10/35 layer ratioof the 4.0 mil (100 μm) film. A possible 5-layer asymmetrical filmstructure can be represented as ABCBD, wherein the “D” layer is adifferent skin material than the “A” material. Another representativebarrier film structure that is useful in making ostomy or collectionbags is a 4-layer asymmetrical structure. This can be represented as“ABCB” wherein the “C” layer is a barrier layer, the “B” layers areadhesive the or bonding layers, and the “A” layer is a skin layer. Inthis case, the exposed “B” adhesive layer can be used to thermally bondor seal two plies of the film together, such as during heat sealing of abag seam.

For ostomy bags, urological collection bags and other appliances whichare worn against the body, it is desired that they exhibit excellenthaptics, softness and comfort. Use of woven and nonwoven laminates orcoverings over the bag is commonly used to eliminate the direct contactof a plastic film against the skin. Direct contact of a smooth film cancause perspiration and “clinging” of the film to the skin, can causeblisters and sores to form due to abrasion against the skin in additionto hot and moist contact, and can promote bacteria or infectious growthbetween the bag and skin of the patient. The barrier properties of thecontainment bag or pouch, which are required to eliminate odorpermeation of the excreted human waste products through the pouch, alsoprevent moisture in the form of skin perspiration from escaping from theregion where the pouch or appliance is worm. Use of a one or two fringedlayers according to the present invention as skin layer or layers ‘A’provides the desired soft skin contact and can allow perspiration toescape from behind the appliance. It is further desired that films withlow flexural or tensile modulus and low durometer “hardness” be used forthe outermost layers of the film so as to provide a softer, moreconformable surface. Elastomeric films, such as those made from TPU,CPE, styrenic block copolymers, ESI and homogeneous polyolefin resins,are especially preferred for coextruded layers on an ostomy orcollection bag. These films also promote quietness, which a desiredattribute of a bag or pouch appliance. A patient wearing a pouch desiresthe appliance not to make any noise or rustling sound while movingaround, as commonly occurs when conventional plastic films are flexed,folded or “crinkled”.

It is additionally desired to utilize plastic tubing and/or plasticfittings or connectors on the film utilized for medical bags, pouches orappliances. These fittings and tubing are usually made of a materialcompatible with the film and bondable to the film. Tubing or fittingsmay be made of polyolefins such as polyethylene, EVA or EMA, or of TPUor flexible vinyl (PVC). Film structure and surface compositions mayneed to be formulated so as to provide suitable bonding via thermalwelding, impulse sealing, high frequency (also known as radio frequency)sealing or mechanical fastening. Additionally, use of liquid curableadhesives or hot melt applied adhesives can be utilized to adhere tubingor fittings to a bag structure.

In yet another aspect, the present invention relates to a floor or wallcovering product comprising a fringed film, sheet or coating accordingto the invention. In a preferred embodiment, the floor or wall coveringis a multi-layer film or sheet comprising at least one layer having afringed surface microstructure. The product may further comprise anoptional print layer, an optional reinforcement layer and/or an optionalfoam backing layer. In a wall covering product, the fringed layer may bepresent as the surface or top layer, the print layer or both. In a floorcovering product, the fringed layer may be the surface layer, the printlayer and/or the backing layer, the fringed microstructure facing thefloor. Used as a surface layer, the fringed microstructure is designedto afford soft touch and feel and may be imprinted, if desired. If thefringed layer serves as a print layer, the fringed microstructure isdesigned to provide proper surface variability and imprintability. Thislayer is imprinted and preferably covered (on the top) by a transparentupper wear layer. As a backing layer the fringed layer affords anti-slipproperties. If present, the reinforcement layer is an intermediate layerproviding dimensional stability to the product, preferably a floorcovering, which can be in excess of 4 meters in width. The optionalintermediate reinforcement layer may be a melt processed polyolefinpolymer or a non-woven or woven textile material. Preferably, theoptionally intermediate reinforcement layer is a non-woven glass fleecematerial or a non-woven polymeric material. If present, the foam backinglayer imparts resilient cushioning properties to the product and canalso impart noise and thermal insulation characteristics to the productas well as provide a barrier against microorganisms. Suitable resilientfoam backing layers comprise or consist of a solvent dispersedpolyolefin polymer, a melt processed polyolefin polymer or a latexcomposition. The product may further contain appropriate additives, e.g.flame retardant additives to insure compliance with flame retardantrequirements and other regulatory requirements.

Examples

The following Examples are illustrative of the invention, but are not tobe construed as limiting the scope thereof in any manner. The followingabbreviations are used: ESI=substantially random ethylene/styreneinterpolymer; MFI or MI=melt flow index (measured at 2.16 kg/190° C.according to ASTM D-1238, condition E); N/T=not tested; the pressuresare indicated in MegaPascal (MPa) and the temperatures are in degreeCelsius.

Example 1 Preparation and Characterization of Fringed Films 1A-1D

FIG. 2 shows a schematic drawing of the calender used to make thefringed film. The calender comprises a steel pre-heat roll (11) with adiameter of 12.7 cm and 9 matrix roll (13) with a total diameter of11.76 cm (10.16 cm diameter steel roll covered on each side with 0.8 cmof Viton™ rubber. The rubber is laser engraved with a regular pattern 00 0 0

of cylindrical dead-end holes (cavities, 2860 per square centimeter)which have a diameter of about 110 microns and a depth of about 270microns. The center to center distances are 185 microns (closestneighbor) and 267 microns (diagonal neighbor).

For Fringed Films 1A and 1B, the (basic) smooth film fed into thecalender via the feeder roll (10) is 100 microns thick and has thefollowing general structure:50% Outer Layer, 30% Core Layer, 20% Backing Layer.

The outer layer which comes in contact with the matrix roll and isconverted into the fringed layer, is made from a blend consisting of 67%of a homogeneous substantially linear ethylene/octene copolymer (30 MI,0.885 g/cc), 27% of a homogeneous substantially linear ethylene/octenecopolymer (30 MI, 0.902 g/cc) and 6% of a Slip Masterbatch containing 5%erucamide in 6 MI, 0.900 g/cc polyolefin plastomer. The core layerconsists of 87% LDPE (0.8 MI, 0.924 g/cc) and 13% TiO₂ Masterbatch (60%TiO₂ in LDPE or LLDPE). The backing layer consists of 92% HDPE (0.29 MI,0.9605 g/cc) and 8% TiO₂ Masterbatch. The process is run with a 21 mils(=533 microns) negative gap width (applied maximum pressure in the gapof about 3-3.5 MPa (=30-35 bar), contact nip width of 12 mm. Line speedis 1 m/min. The winder speed is equal to line speed plus the necessarydelta to maintain the given peel angle. The temperature of the chillroll (15) is 15° C. Hydraulic Pressure is the fluid pressure measured atthe inlet to the pistons which apply pressure to the axis of the matrixroll. In this particular configuration the matrix roll presses againstthe pressure (preheat) roll. Film off the matrix roll is measured nearpoint P₁ in FIG. 3. Matrix roll temperature is measured at angle (α)=90degrees (see FIG. 3).

FIG. 3 shows the parameters used in the calculation of the release angle(β) which is based on the equipment variables a (=4 inches), b (=2inches), c (=1.38 inches), and d (=2.315 inches) as defined in FIG. 3,and on the wrap angle of the matrix roll (13). β is the angle betweenthe tangent to rubber roll at the point of detachment and the film. Theangle is derived based on the rules of analytic geometry.

In FIG. 3, O₁ is the point of origin of the circle C₁, O₂ is the pointof origin of the circle C₂, P₁ is the point of detachment from thematrix roll (13). P₂ is the point of touch to the chill roll (15), L isthe length of the segment connecting P₁ to P₂, β is the angle betweenthe tangent to the matrix roll (13) at the point of detachment P₁ andsegment L. Based on the method of calculation detailed below, therelease angle calculates as 112.3.

The calculation of release angle is based on FIG. 3:

The length of the line segment L is given by,L=[[a+c+d·(1−cos α)]²+(d·sin α−b)²−a²]^(0.5)

Replacing the origin of a rectangular coordinate system at O₁, thecoordinates of the point P₂, (X,Y) have to be calculated. Equation(1)below describes a circle with radius L and origin P₁. Equation(2)describes the circle C₂ with radius a and origin O₂.L=(x+d·sin α)²+(y−d cos α)²  Equation (1)a ²=(x+b)² +[y−(d+c+a)]²  Equation (2)

The values (X,Y) are obtained by solving Equations (1) and (2)simultaneously. This is equivalent to finding the points of intersectionbetween the circles described by Equations (1) and (2).

The tangent to circle C₁ at P₁ is:m₁=tan α

The slope of the line segment L is$m_{2} = \frac{Y - {{d \cdot \cos}\quad\alpha}}{X + {{d \cdot \sin}\quad\alpha}}$

The angle between L and the tangent to C₁ at P₁ is$\beta = {\tan^{- 1}\left( \frac{m_{2} - m_{1}}{{m_{1} \cdot m_{2}} + 1} \right)}$

Because the intersection of the two lines gives rise to twocomplementary angles, the proper angle corresponding to ● is chosen byconsidering the geometry for given sets of equipment variables and wrapangle. For ●=60, ● is calculated as 112.3 degrees.

The calculation of the release angle assumes that the peeling is abruptand the flexural modulus of the film is low. Sticky fringes may reducethe actual peel angle because they prevent the desired abrupt peeling.Furthermore, any bending moment in the film may reduce the peel angle.The following table correlates wrap angle and release or peel angle.

Wrap Angle Calculated Peel Angle 0 25 15 45 30 68 45 90 60 112 75 133 90151

The dimensional parameters characterizing the fringed microstructure aremeasured using a WYKO NT3300 Optical Profiler and the Vertical ScanningInteferometry (VSI) mode. The sampling area is 460×600 square microns.

The following process conditions are used to produce Fringed Film 1A:

-   Wrap Angle: 75-90°-   Peel Angle: 133-151°-   Hydraulic Pressure (MPa): 17-   Preheat distance on pressure roll: 4.5 cm-   Film Temperature into gap: 98° C.-   Film Temperature off Matrix Roll: 51° C.-   Matrix Roll Surface Temperature: 61° C.-   Pressure Roll Surface Temperature: 126° C.-   Air Knife Delta: 20° C.    Preheat distance is the distance that the film is in contact with    the preheat roll. The amount of preheat is dependent upon the    distance and the line speed. Air knife delta is defined as the    reduction in the matrix roll surface temperature as achieved by    applying surface air to the back of the matrix roll as the process    is running.

The fringe characteristics of Fringed Film 1A, as determined by opticalsurface profilometry, are as follows:

-   Fringe height (H): 237 microns-   Fringe Diameter at base (D): 155 microns-   Surface Area Ratio: 9.6-   Hollow Depth Ratio (●): 1.1-   Hollow Diameter Ratio (●): 0.52-   Hollowness Index (●): 57-   Aspect Ratio: 1.5

The following process conditions are used to produce Fringed Film 1B:

-   Wrap Angle: 60-75°-   Peel Angle: 112-133°-   Hydraulic Pressure (MPa): 17.1-   Preheat distance on pressure roll: 22.5 cm-   Film Temperature into gap: 91° C.-   Film Temperature off Matrix Roll: 46° C.-   Matrix Roll Surface Temperature: 59° C.-   Pressure Roll Surface Temperature: 115° C.-   Air Knife Delta: 13° C.    Preheat distance is the distance that the film is in contact with    the preheat roll. The amount of preheat is dependent upon the    distance and the line speed. Air knife delta is defined as the    reduction in the matrix roll surface temperature as achieved by    applying surface air to the back of the matrix roll as the process    is running.

The fringe characteristics of Fringed Film 1B, as determined by opticalsurface profilometry, are as follows:

-   Fringe height (H): 220 microns-   Fringe Diameter at base (D): 175 microns-   Surface Area Ratio: 5.7-   Hollow Depth Ratio (●): 0.5-   Hollow Diameter Ratio (●): 0.35-   Hollowness Index (●): 18-   Aspect Ratio: 1.3

A smooth film (with a thickness of 100 microns) of the followingstructure and composition is used to make Fringed Film 1C:50% Outer Layer, 30% Core Layer, 20% Backing Layer.

The outer layer which comes in contact with the matrix roll and isconverted into the fringed layer, is made from a blend consisting of 52%of a homogeneous substantially linear ethylene/octene copolymer (30 MI,0.885 g/cc), 22% of a homogeneous substantially linear ethylene/octenecopolymer (30 MI, 0.902 g/cc), 20% of an ethylene/inyl acetate copolymer(8.0 MI, 12% VA) and 6% of a Slip Masterbatch containing 5% erucamide in6 MI, 0.900 g/cc polyolefin plastomer. The core layer consists of LDPE(0.7 MI, 0.922 g/cc). The backing layer consists of HDPE (0.3 MI, 0.947g/cc).

The process is run with a negative gap width of 12 mils (=300 microns)(applied maximum pressure in the gap of about 2.5 MPa (=25 bar), contactnip width of 9 mm). Line speed is 1 m/min. The winder speed is equal toline speed plus the necessary delta to maintain the given peel angle.The temperature of the chill roll is 200 C.

The following process conditions are used to produce Fringed Film 1C:

-   Wrap Angle: 15°-   Peel Angle: 450-   Hydraulic Pressure (MPa): 16.5-   Preheat distance on pressure roll: 22.5-   Film Temperature into gap: 91° C.-   Film Temperature off Matrix Roll: 75° C.-   Matrix Roll Surface Temperature: 75° C.-   Pressure Roll Surface Temperature: 117° C.

The fringe characteristics of Fringed Film 1C, as determined by opticalsurface profilometry, are as follows:

-   Fringe height (H): 335 microns-   Surface Area Ratio: 17.4-   Hollow Depth Ratio (●): 1.0-   Hollow Diameter Ratio (●): 0.76-   Hollowness Index (●): 76-   Aspect Ratio: 2.8    Fringed Film 1C shows that the presence of a polar comonomer in the    fringed layer results in long(er) fringes with a high(er) Hollowness    Index.

A smooth film (with a thickness of 100 microns) of the followingstructure and composition is used to make Fringed Film 1D:50% Outer Layer, 30% Core Layer, 20% Backing Layer.

The outer layer which comes in contact with the matrix roll and isconverted into the fringed layer, is made from a substantially randomethylene/styrene interpolymer containing 30% of styrene comonomer (25MI). The core layer consists of LDPE (0.7 MI, 0.922 g/cc). The backinglayer consists of HDPE (0.3 MI, 0.947 g/cc).

The process is run with a negative gap width of 12 mils (=300 microns)(applied maximum pressure in the gap of about 2.5 MPa (=25 bar), contactnip width of 9 mm). The line speed is 1 m/min, the chill rolltemperature is 20° C.

The following process conditions are used to produce Fringed Film 1D:

-   Wrap Angle: 300-   Peel Angle: 680-   Hydraulic Pressure (MPa): 17.6-   Preheat distance on pressure roll: 4.5 cm-   Film Temperature into gap: 49° C.-   Film Temperature off Matrix Roll: 54° C.-   Matrix Roll Surface Temperature: 55° C.

The fringe characteristics of Fringed Film 1D, as determined by opticalsurface profilometry, are as follows:

-   Fringe height (H): 174 microns-   Surface Area Ratio: 3.65-   Hollow Depth Ratio (●): 0.48-   Hollow Diameter Ratio (●): 0.55-   Hollowness Index (●): 26-   Aspect Ratio: 1.5

Example 2 Scanning Electron Microscopy (SEM) of a Fringed Film

A three-layer fringed film (layer ratios: 60% fringed layer/20% core/20%outside) is evaluated using Scanning Electron Microscopy. The fringedlayer, namely the layer with the fringed surface microstructure, is madefrom a blend of 6 weight percent of slip masterbatch, 27 weight percentof a homogeneous ethylene/octene copolymer having a density of 0.885g/cc and a MFI of 30 g/10 min and 67 weight percent of a homogeneousethylene/octene copolymer having a density of 0.902 g/cc and a MFI of 30g/10 min. The core layer is made from 85 weight percent of a LDPE havinga density of 0.923 g/cc and a MFI of 0.7 g/10 min(LDPE 300R availablefrom The Dow Chemical Company) and 15 wt. % White Masterbatch. Theoutside layer is made from 94 weight percent of a LLDPE having a densityof 0.912 g/cc and a MFI of 1.0 g/10 min (ATTANE™ SL 4101 resin availablefrom The Dow Chemical Company), and 6 weight percent of WhiteMasterbatch.

A portion of the fringed film is cut and mounted on an aluminum samplestub with conductive carbon tape and carbon paint. The sample is coatedwith approximately 60 Angstroms of chromium using a Denton Hi-Res 100chromium sputtering system, then examined and photographed using aHitachi S-4100 FEG SEM. All photographs are taken at 2.0 kV acceleratingvoltage. Photographs are taken at 50×, 250×, and 500× magnification.

When magnified using the SEM technique, the top view surface of the filmexhibits a pattern or matrix of hollow tubes or cylinders that emergefrom the base film. One is able to see into the tube as it is open ontop but closed at the bottom by the base film. Such hollow tubes canalso be described as craters. The walls of the craters or tubes areraised from the base film. The cross-sectional view of the film, cuttingthrough the center of the tubes, exhibits peaks for the walls of thetubes or craters, followed by valleys which exhibit the crater holesthemselves as well as the surface of the base film which is between thecraters as dictated by the base pattern.

Example 3 Fringed Film treated by Electron Beam Crosslinking

Specimens of the fringed film of Example 2 are treated via electron beamcrosslinking. The film specimens are placed in cardboard fileholders andirradiated using a 12 MeV, 10 kW electron beam source at SterigenicsInternational, Inc. (San Diego, Calif.). The radiation dose per pass is32 kGrays (3.2 Mrad). Three fringed specimens are exposed to the beammultiple times to give total dosage levels of 160, 288 and 448 kGray(16, 28.8, 44.8 Mrad), respectively. The gel content (insolublefraction) of the crosslinked films is determined by xylene extractionper ASTM D2765 method, Procedure A with two exceptions. The films arenot conditioned and are tested as received without grinding. The ASTMD-2769 method involves placing about 0.3 g of sample into a sampleholder made of stainless steel wire cloth. The sample holder is thenimmersed into a three neck round bottom flask containing xylene boilingin reflux condition and an antioxidant (0.85% (w/v)2-2′-methylene-bis-(4-methyl-6-tertiary butyl phenol)). Samples are keptin xylene for 12 hours and are then transferred to a vacuum ovenpreheated to 150° C. The samples are dried in the oven for 12 hoursunder at least 28 in Hg vacuum. After an hour of cooling the sampleholders are weighed. The difference in weight before and afterextraction is used in the calculation of gel content. The results of thegel testing are as follows:

% Gel Sample Radiation Dose, kGy (Average) Sample 3-A 160 20.3 Sample3-B 288 48.6 Sample 3-C 448 54.6

Samples 3-A, 3-C, and a non-crosslinked control are also exposed to heatusing a hot plate to evaluate the ability of the various samples tomaintain their surface texture. The samples are mounted on glass slides,then placed on a hot plate and exposed to 60°, 70°, 80°, 90° and 110°Celsius. each for 10 minutes. After being cooled to room temperature,the films are evaluated using the SEM technique described in Example 2to determine the ability of the fringed surface observed at roomtemperature to remain intact. At room temperature the surface of thetubes or craters is very sharp or vivid. The edges of the frayed topsare very thin and wispy in nature. The tops of some of the tubes orcraters appear to overlap or touch the surfaces of the other tubes(Condition 0). As the surface becomes affected by rising temperature thefrayed, thin, wispy tops first begin to become more isolated with lessoverlapping to other craters indicating that they are beginning toshrink back to the domain of their tube (Condition 1.0) and theneventually there is no overlapping of the wispy tops (2.0). Withincreasing heat the tops of the surfaces become more regular and ovaland appear to be thicker and not at all frayed or wispy and the distancebetween the tubes or craters becomes smaller as do the distances betweenthe craters (Condition 3). Eventually the diameter of the crater becomesmuch smaller as do the distances between the craters as the wall shrinkscloser to the base of the film. At this point the definition of thecraters is considerably less discernable than Condition 3 but stillobservable (Condition 4). The final view is when the craters havecompletely shrunk back into the base of the film and are no longerdiscernable (Condition 5). The rating of the various samples areprovided below.

Temperature Control Sample 3-C Sample 3-A 25° C. Condition 0 N/T N/T 60°C. Condition 1 Condition 0 N/T 70° C. Condition 1 Condition 0 N/T 80° C.Condition 2 Condition 1 N/T 90° C. Condition 2 Condition 1 Condition 2110° C.  Condition 5 Condition 3 Condition 4

As observed by SEM the highest level of crosslinking (Sample 3-C)appears to postpone the loss of the frayed, wispy appearance until 80°Celsius. as compared to the 60° Celsius. for the non-crosslinkedcontrol. The lowest and highest level of crosslinking both prevent thesurface from completely melting at the 110° C., with the highest levelof crosslinking keeping it most intact.

This example demonstrates the ability of cross-linked fringed films toincrease the upper service temperature of the films. Applicationsbenefiting from enhanced temperature resistance include, for example,automotive interior applications such as fabric or vinyl door panels,instrument panels, dash boards and headliners, as well as outdoorfurniture cushion covers (capable of withstanding high temperatures inArizona sun or attic conditions).

Example 4 Printing Tests

I. The film of Example 2 is evaluated for printability. The firstprinting test involves a non-contact printing apparatus, a Marsh LCP ML4Ink Jet System which is used to print polyethylene heavy duty shippingsacks. The ink used is a methyl ethyl ketone based Printing Ink by MarshCalled UN 1210 FD. The FD indicates fast drying. The bags move by on aconveyor belt and when they pass an electronic eye the lot number orproduct type is printed on the side of the bag in a macro dot matrixform. The tested versions are a non-textured control sample and afringed film sample, each having the structure and composition of thefilm of Example 2. Approximately 4 inch×4 inch samples are taped to theside of a bag which is run past the electronic eye.

Printed Appearance: the printed appearance of the control film is veryglossy and one can see the raised ink dots which sit on the top of thefilm. The fringed film has a mat finish and the dots do not at allappear raised but sunk into the film. It has a softer appearance.

Smudge/Smear Test within 30 seconds the bags are tested for smudging bylightly wiping a finger across the surface of each specimen. None of thespecimens exhibits smudging.

Ink Adhesion: immediately following the smudge test, the bags areevaluated for ink adhesion. Strips of adhesive tape approximately 0.5inch×2 inch are pressed with moderate but consistent pressure across thesurface of each film and are then peeled away from the films. Aqualitative analysis gives the following results:

-   -   non-textured control film: approximately 60-75 percent of each        ink dot is removed;    -   fringed film: approximately 10-20% of each ink dot is removed.

The fringed sample exhibits significantly improved ink adhesion relativeto the non-textured sample. Even after applying the adhesive tape withdramatically higher pressures to the fringed sample the removal of inkis still approximately half of what is observed with the non-texturedfilm with the tape applied only at moderate pressures. The level of inkadhesion to the films after a week of sitting at room temperatureremains consistent with what is observed immediately after the printing.

Ink Abrasion/Scratchability: the specimens are also evaluated by simpleabrasion and scratch tests. The abrasion test involves wiping a pencileraser head across a single dot in a back and forth motion until itappears that no change in the color intensity of the dot is observed byadditional wiping. The scratch test involves scraping a moderately sharpimplement such as a coin or a fingernail across the printed film surfaceand observing the ability of the ink to remain in place. The results ofthese two tests are described below.

Sample Abrasion Test Scratch Test Non-Textured Within 5 strokes of theInk is easily scraped off by Film eraser the surface ink dot scraping asharp is removed and only a implement across the light stain remainedsurface. Entire dots can below. be removed after repeated scrapings witha light stain remaining below. Fringed Film After 25 strokes of theSingle swipes across the eraser the ink dot is still dots reveal noobvious not removed from the film change in the ink dots. surface andthe remaining Repeated swipes are able dot looks significantly tolighten the dots but do darker than the light stain not approach inkremoval of the non-textured film achieved by the eraser.

II. Another printing test involves evaluation of a three-layer fringedfilm (layer ratios: 50% fringed/30% core/20% outside) of the followingcomposition:

fringed layer: 6 wt. % slip masterbatch, 27 wt. % of a homogeneousethylene/octene copolymer having a density of 0.885 g/cc and a MFI of 30g/min, 67 wt. % of a homogeneous ethylene/octene copolymer having adensity of 0.902 g/cc and a MFI Of 30);

-   -   core layer 87 wt. % LDPE 300R, 13 wt. % White Masterbatch;    -   outside layer 92 wt. % ATTANE SL 4101, 8 wt. % White        Masterbatch.

The fringed film is evaluated on an ink jet desktop printer typicallyused for printing paper items. A smooth (non-textured) base film of thecorresponding structure and composition is used as control film.

Appearance of the films: on the non-textured film ink beads up on thesurface and wetted well outside of the boundary of the dot patterncommon to ink jet printers. The appearance is blurred. The fringed filmdoes not bead up and shows significantly better definition of the dotpattern. In addition, it has a very matte finish and appears to have theappearance of a soft-colored pencil look as opposed to a typical inklink. The physical multi-dimensionality of the film surface appears tocreate a visual three-dimensional appearance as well. This effectprovides an enhanced and improved visual appearance giving a greaterdepth or creating a better shading effect by alternating colors. Suchsoft shading effect or multidimensional effect can benefit variousapplications for which the (visual and haptic) depth appearance of atextile in combination with the cleanability of a plastic are desiredincluding, for example, doll skins and automotive seats.

Smudge test: a finger smudge test is conducted after 12 hours revealingthat ink on both the non-textured control and the fringed film is notcompletely dry. The ink on the non-textured film smudges beyond theboundaries of the printed object and smears onto the rest of the film.The ink on the fringed film comes off on the finger, but does not appearto smudge beyond the boundary of the printed object. This finding couldindicate that the ink on the fringed is more firmly encapsulated in thehollow tubes of the film.

Inspection by microscopy of the top view of the ink jet printed fringedsurface reveals that the ink resides on the tips of the fringe, inbetween the fringe, as well as in the recessed centers of the craters.

Example 5 Pouch Comprising a Multi-Layer Fringed Film

A coextruded 5-layer barrier film is made on a conventional upward blown5-layer film line. The 5.0 mil (125 μm) thick film is comprised of aoutermost layer of homogeneous polyethylene copolymer, an EVA adhesivethe layer, a PETG core barrier layer, an EVA adhesive be layer, and aULDPE-LDPE blend innermost skin layer (ABCBD structure). The outermostlayer is 50% (2.5 mil, 62 μm) of the film gauge and consists of 96%Affinity™ SM1300 (The Dow Chemical Company, 0.902 g/cc, 30 g/10 MFI) and4% CN4420 slip/antiblock concentrate (20% silicon dioxide, 3.5%stearamide, 3.5% erucylamide in EVA resin). The two EVA tie layers areeach 10% (0.5 mil, 12 μm) of the film gauge and consist of 100% Elvax™3190 (DuPont, 25% vinyl acetate, 0.95 g/cc, 2.0/10 MFI). The core PETGcopolyester layer is 10% (0.5 mil, 12 μm) of the film gauge and consistsof 100% Eastar™ 6763 PETG (Eastman Chemical Company, 1.27 g/cc, 0.70inherent viscosity). The innermost skin layer is 20% (1.0 mil, 25 μm) ofthe film gauge and consists of a blend of 60% Attane™ 4201 ULDPE (TheDow Chemical Company, 0.912 g/cc, 1.0 g/10 minute melt index) and 40%LDPE 6811 (The Dow Chemical Company, 0.922 g/cc, 1.2 g/10 minute meltindex).

The Affinity™ layer is extruded at a temperature of 280° F. (138° C.);the EVA layers are extruded at 325° F. (163° C.); the PETG layer at 400°F. (204° C.) and the ULDPE-LDPE innermost layer is extruded at 340° F.(171° C.). The 5 inch (12.7 cm) diameter tubular blown film die isheated at 340° F. (171° C.). After cooling the blown tube with a duallip air ring, the tube is collapsed to form a 15 inch (38 cm) wide layflat, slit into two separate webs and wound into film rolls.

In a separate operation and using the equipment described in Example 1and FIG. 2, the film is subjected to a fringing process, wherein theoutermost Affinity™ layer is provided with a fringed surfacemicrostructure. The fringe length is about 300 μm.

The resulting fringed film exhibits a soft, velour or fabric-type feel.Closed ended pouches of the fringed film are fabricated using a heated1-liter bag die mounted on a heated press (Sentinel 808 heat sealer)using a temperature of 325° F. (163° C.) and 4 second dwell. Two pliesof the film are oriented such that the fringed Affinity™ resin layer ofeach ply is on the outside of the pouch and the ULDPE-LDPE blend layeris on the inside with the heat seal causing the ULDPE-LDPE layer of oneply to bond to the same layer of the second ply around the perimeter ofthe pouch die. Films are tested for machine direction (MD) andtransverse direction (TD) physical properties according to ASTM D-882both before fringing (initial base film) and after fringing (fringedfilm). In addition, oxygen transmission rate (O₂TR) is tested accordingto ASTM D-3985 using a Mocon Ox-Tran 1050 permeability tester and watervapor transmission rate (WVTR) is tested according to ASTM F-1249 usinga Mocon Permatran W-600 permeability tester.

A 4-layer coextruded fringed film similar to that described above isproduced, with the modification that the 10% PETG core barrier layer isreplaced with a 10% layer of PVDC. A blend of 96% Saran™ 469 PVDC (TheDow Chemical Company) and 4% Elvax™ 3180 EVA (DuPont, 28% vinyl acetate,0.95 g/cc, 25 g/10 MFI) is extruded at 310° F. (154° C.) in thecentermost layer of the 5 layer asymmetrical structure. The resultingfilm is subjected to fringing as described above.

Example 6 Coefficient of Friction (COF)

A smooth base film (6A) (control), a fringed film (6B) having a fringeheight (H) of 70 microns (6B) and a Hollowness Index (●) of 43, and afringed film (6C) having a fringe height (H) of 95 microns and aHollowness Index (●) of 60 are tested for their frictional behavior. Allfilms are three-layer films and have the same structure and compositionof the film 1A described in Example 1. Fringe height (H) and HollownessIndex (●) are determined via optical microscopy using an Olympus Vanox-SModel AH-2 research microscope and the following instrument conditions:transmitted light using Nomarski interference contrast at magnificationsof 100× and 200× with a Polaroid DMC le digital camera. The samples areprepared as follows: cross sections having a thickness of 2.5 micronsare taken from a portion of the film with a diamond knife on a LeicaUltracut-UCT equipped with an FCS cryosectioning chamber. Films havingshort fringes (<75 microns in length) are cut at −120° C. Films havinglonger fringes are embedded in Paraplast™ wax (a tissue embedding mediummanufactured by Oxford Labware). Embedding consists of placing a fewdrops of melted wax on the film surface with the fringes. The samplesare placed in a vacuum oven at 55° C. and 30 in Hg. for approximately 30minutes. The cross sections are placed on glass slides containing asuitable immersion oil and analyzed.

The kinetic coefficient of friction according to ASTM method D1894 ismeasured for different surfaces:

-   -   a) Fringed side of film (or corresponding side for film 6A) to        metal    -   b) Fringed Side of Film to Fringed Side of Film    -   c) Wet Fringed Side of Film to Wet Metal.

For test c), the ASTM method is slightly modified. The film is soaked indeionized water at ambient temperature for 24 hours prior to testing.The metal surface is covered with water, 1-3 mm deep.

The results of test a) (fringed vs. metal) show that fringing causes anincreased COF as compared to the smooth film. The average COF of 5measurements measured on the fringed films 6B (COF=1.2) and 6C(COF=2.65)is significantly higher than the COF measured for film 6A (COF=0.1). Theresults of test b) (film vs. film) show that fringing causes anincreased COF as compared to the smooth film. The average COF valuesmeasured for films 6A, 6B and 6C are 0.2, 0.3 and 1.4, respectively. TheCOF for film 6C is found to increase over the distance traveled by thesled (tested range: 0 to 400 inches). The results of test c) (wet filmvs. wet metal) show that the fringe must be of a certain length toobtain increased COF versus the base. The average COF values measuredfor films 6A, 6B and 6C are 0.1, 0.1 and 1.1, respectively. The COFvalues for films 6B and 6C are found to increase over the distancetraveled by the test (range tested: 0 to 400 inches).

Example 7 Hot Tack Testing

Hot tack testing is accomplished using a Topwave Hot Tack Tester Model52D. The test is conducted at 40 psi bar pressure, 0.5 sec dwell time,0.2 sec delay and 200 mm/min peel speed. The hot tack tests areconducted on the samples, whereby one inch wide strips of film are cutand the matrix layer is folded over and pressed to itself by the hottack tester. The hot tack tester stays closed for the specified dwelltime, it releases the jaws for the delay time and the seal is pulled atthe designated peel speed. Hot tack seals are made at 10° Celsiusincrements from 80-150° C. Celsius. Hot tack initiation temperature isdefined as the point at which the hot tack strength achieves 2 N/2.54cm. The ultimate strength achieved over the tested range is called theultimate hot tack strength.

A smooth base film (7A) (control) and a fringed film (7B) having afringe height (H) of 250 microns (7B) are tested for their hot tackperformance. Both films are three-layer films and have the structure andcomposition of film 1A described in Example 1, above. Fringe height (H)is determined via optical microscopy according to the method describedin Example 6. As compared to the base film 7A, the fringed film 7B showsan improvement, that is decrease in hot tack initiation temperature of12° C. (83° C. for 7B, 95° C. for 7A) and in ultimate hot tack (4.26 for7B, 2.78 for 7A). The ultimate hot tack strength is found to increasewith increasing fringe heights.

Example 8 Water Repellency of Fringed Film

To examine the water repellency or water management characteristics offringed film the water contact angle test is utilized. Testing is doneaccording to ASTM-D5946 utilizing method 1 in 3.1.2.1. In this testmethod water droplets are placed on the surface of a film sample, andthe contact angle values are then averaged. The contact angle ismeasured directly with a protractor by using a tangential alignment of acrosshair line to the point at which the side of the water dropletcontacts the substrate. Water contact angle can then be related to awetting tension via a conversion chart. The test is used to compare theeffect the fringed surface microstructure has on the water repellency orthe ability to enable the water to bead up on the surface. The watercontact angle is measured using pH 7 buffer solution.

The test is performed on films having the same structure, compositionand fringe characteristics as films 6B and 6C described in Example 6 andare referred to as film 8A (fringe height (H) of 70 microns) and 8B(fringe height (H) of 95 microns) in this example. Two separate areasper film were evaluated and the values averaged. The average watercontact angle determined for film 8A is 137.3, the average water contactangle for film 8B is 155.4. The results show that increased fringelength results in an increased water contact angle, indicating anincreased ability to bead up water on the surface. Such effect isimportant for applications requiring water repellency, such as raincoatsand other water repellant outerwear, house wraps, feminine hygiene anddiaper top sheets, and (latex) gloves (prevent formation of a slipperysurface).

1. A mono-layer or multi-layer film, sheet, or coating comprising atleast one layer that displays a surface microstructure, which layer is athermoplastic polymeric material having fringes, wherein said fringesare non-perforated and are at least partially hollow with at least about25 percent of the volume at the top of the fringe being empty and have aheight of at least about 40 microns or more, in a density of 1000 ormore per square centimeter.
 2. A film, sheet or coating according toclaim 1, wherein the fringes have a height in the range of from 40microns to 1 millimeter.
 3. A film, sheet or coating according to claim1, wherein the fringes have a hollow depth ratio, which is the ratio ofthe average inner height to the average maximum height of the fringe, of1.3 or lower, as determined by optical surface profilometry.
 4. A film,sheet or coating according to claim 1, wherein the fringes have a hollowdiameter ratio, which is ratio of the diameter of the hollow center athalf height and the diameter at the bottom of the fringe, of 1 or lower,as determined by optical surface profilometry.
 5. A film, sheet orcoating according to claim 1, wherein the fringes have a HollownessIndex of 100 or lower, as determined by optical surface profilometry. 6.The film, sheet or coating according to claim 1, wherein the fringeshave an aspect ratio, which is the ratio of the fringe height and thefringe diameter, of between 1 and
 5. 7. The film, sheet, or coatingaccording to claim 1, wherein the thermoplastic material is cured,irradiated or cross-linked.
 8. The film, sheet, or coating according toclaim 1, wherein the layer displays a surface microstructure on bothsides.
 9. The film, sheet, or coating according to claim 1, which is amono-layer film, sheet or coating.
 10. The film, sheet, or coatingaccording to claim 1, which is a multi-layer film, sheet or coating. 11.The film, sheet, or coating according to claim 10, wherein the surfacemicrostructure is on an outer layer.
 12. The film, sheet, or coatingaccording to claim 1 which is a multi-layer film, sheet or coating,wherein the surface-structured layer is an interlayer.
 13. The film,sheet or coating according to claim 10, wherein at least one of theouter layers is a fringed layer and at least one of the inner layers isan oriented film, preferably a biaxially oriented polypropylene film.14. The film, sheet or coating according to claim 13, wherein at leastone of the layers is a foamed layer.
 15. The film, sheet, or coatingaccording to claim 1, wherein at least one layer is elastic.
 16. Thefilm, sheet, or coating according to claim 1, which is oriented.
 17. Thefilm, sheet, or coating according to claim 1, wherein at least one layeris vapor permeable and liquid impermeable.
 18. The film, sheet, orcoating according to claim 1 which is printed or imprinted.
 19. Thefilm, sheet or coating according to claim 1 wherein the surfacemicrostructure has been subjected to a post treatment step selected fromthe group consisting of treatment with an abrading device, coronatreatment, curing, irradiation and crosslinking.
 20. A compositecomprising a mono-layer or mufti-layer film, sheet, or coating whereinat least one layer displays a surface microstructure, which layer is athermoplastic polymeric material and characterized by fringes, whereinsaid fringes are non-perforated and are at least partially hollow withat least about 25 percent of the volume at the top of the fringe beingempty and have a height of at least about 40 microns or more, in adensity of 1000 or more per square centimeter.
 21. The compositeaccording to claim 20 which is a laminate.
 22. An article of manufacturecomprising a mono-layer or multi-layer film, sheet, or coating whereinat least one layer displays a surface microstructure, which layer is athermoplastic polymeric material and characterized by fringes, whereinsaid fringes are non-perforated and are at least partially hollow withat least about 25 percent of the volume at the top of the fringe beingempty and have a height of at least about 40 microns or more, in adensity of 1000 or more per square centimeter.
 23. The article ofmanufacture according to claim 22, which is a glove.
 24. The article ofmanufacture according to claim 22, which is a hygienic product.
 25. Thearticle of manufacture according to claim 22, which is a medicinalcollection bag.
 26. The article of manufacture according to claim 22,which is a floor or wall covering product.
 27. The article ofmanufacture according to claim 22 which has a soft touch.
 28. Thearticle of manufacture according to claim 22 which is water repellant.29. The article of manufacture according to claim 28 which has anti-skidproperties.
 30. The article of manufacture according to claim 22 whichhas enhanced carrying, capturing or storing properties.
 31. The articleof manufacture according to claim 22 which is heat resistant.
 32. Aprocess for making the mono-layer or multi-layer film, sheet, or coatingaccording to claim 1, said process comprising forming a precursor film,sheet, or coating with a surface characterized by a pattern of peaks andvalleys in a continuous compression molding process, and subjecting saidprecursor to mechanical treatment comprising the application of atractive force which is applied during release of the film, sheet orcoating from a matrix surface under conditions allowing the formation ofa fringed surface microstructure.
 33. The process according to claim 32,wherein application of the tractive force comprises peeling the film,sheet, or coating off the matrix surface at a temperature which is at orbelow the Vicat softening point of the thermoplastic material and at arelease angle of between 20 and 170 degrees relative to the matrixsurface.
 34. The process according to claim 32, wherein the precursor isa foam.